<PAGE>   1
                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   FORM 10-Q

     [X] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

               For the quarterly period ended SEPTEMBER 30, 1999
                                              ------------------


                       Commission File Number : 001-14575


                          VISTA ENERGY RESOURCES, INC.
                          ----------------------------
             (Exact name of registrant as specified in its charter)


                  Delaware                             75-2766114
                  --------                             ----------
       (State or other jurisdiction of              (I.R.S. Employer
       incorporation or organization)              Identification No.)

 550 West Texas Avenue, Suite 700, Midland, Texas         79701
 ------------------------------------------------         -----
    (Address of principal executive offices)            (Zip Code)

                                 (915) 570-5045
                                 --------------
              (Registrant's telephone number, including area code)

                                      NONE
                                      ----
              (Former name, former address and former fiscal year,
                         if changed since last report)


Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Act of 1934
during the preceding 12 months (or for such shorter period that the registrant
was required to file such reports) and (2) has been subject to such filing
requirements for the past 90 days. Yes [X] No [ ]

Indicate the number of shares outstanding of each of the issuers classes of
common stock, as of the latest practicable date:

                   Class                  Outstanding as of November 1, 1999
       Common stock, $.01 par value                    16,367,328



<PAGE>   2

                          VISTA ENERGY RESOURCES, INC.
          FORM 10-Q FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 1999



                                     INDEX

<TABLE>
<CAPTION>
    PART I.       FINANCIAL INFORMATION                                               Page
                                                                                      ----
<S>               <C>                                                                 <C>

    Item 1.       Financial Statements

                  Consolidated Balance Sheets
                  at September 30, 1999 (Unaudited) and December 31, 1998 (Audited)     3

                  Unaudited Consolidated Statement of Operations
                  for the Three and Nine Months Ended September 30, 1999 and 1998       4

                  Unaudited Consolidated Statement of Cash Flows
                  for the Nine Months Ended September 30, 1999 and 1998                 5

                  Notes to Unaudited Consolidated Financial Statements                  6

    Item 2.       Management's Discussion and Analysis of Financial Condition
                  and Results of Operations                                             13

    PART II.      OTHER INFORMATION                                                     21

    Item 1.       Legal Proceedings

    Item 2.       Changes in Securities

    Item 3.       Defaults Upon Senior Securities

    Item 4.       Submission of Matters to a Vote of Security Holders

    Item 5.       Other Information

    Item 6.       Exhibits and Reports on Form 8-K

                  Signatures
</TABLE>




                                       2
<PAGE>   3


                         PART I - FINANCIAL INFORMATION

ITEM 1.  FINANCIAL STATEMENTS

                          VISTA ENERGY RESOURCES, INC.
                          CONSOLIDATED BALANCE SHEETS

<TABLE>
<CAPTION>
                                   ASSETS                               SEPTEMBER 30,    DECEMBER 31,
                                                                            1999             1998
                                                                        ------------     ------------
                                                                         (UNAUDITED)       (AUDITED)
<S>                                                                     <C>              <C>
CURRENT ASSETS:
  Cash and cash equivalents                                             $     20,623     $         --
  Accounts receivable:
     Oil and gas sales                                                     3,685,493        1,498,727
     Trade                                                                   636,578          900,401
  Other                                                                      273,365          262,218
                                                                        ------------     ------------
         Total current assets                                              4,616,059        2,661,346
PROPERTY AND EQUIPMENT:
  Oil and gas properties, based on successful efforts accounting          92,010,743       86,970,665
  Other                                                                      566,830          529,771
                                                                        ------------     ------------
                                                                          92,577,573       87,500,436
  Less accumulated depreciation, depletion and amortization              (34,462,776)     (30,956,448)
                                                                        ------------     ------------
   Property and equipment, net                                            58,114,797       56,543,988
OTHER ASSETS, NET                                                            901,607          537,983
                                                                        ------------     ------------
         Total Assets                                                   $ 63,362,463     $ 59,743,317
                                                                        ============     ============
                      LIABILITIES AND STOCKHOLDERS' EQUITY
CURRENT LIABILITIES:
  Accounts payable                                                         4,380,516        2,829,495
  Accrued expenses                                                           462,633          259,117
                                                                        ------------     ------------
         Total current liabilities                                         4,843,149        3,088,612
LONG-TERM DEBT                                                            52,633,740       50,730,894
DEFERRED TAX LIABILITY                                                       431,117          350,000
OTHER LONG-TERM LIABILITIES                                                  205,116          205,116
STOCKHOLDERS' EQUITY:
      Common Stock, par value $.01 per share;
      Authorized - 50,000,000 shares; issued 16,367,328 at September         163,736          163,736
        30, 1999 and December 31, 1998, respectively;                       (212,070)        (212,070)
       Treasury Stock - 6,300 shares
      Additional paid in capital                                          25,071,099       25,071,099
      Retained earnings (deficit)                                        (19,503,424)     (19,654,070)
                                                                        ------------     ------------
         Total stockholders' equity                                        5,519,341        5,368,695
                                                                        ------------     ------------
         Total liabilities and stockholders' equity                     $ 63,632,463     $ 59,743,317
                                                                        ============     ============
</TABLE>


              The accompanying notes are an integral part of these
                       consolidated financial statements.


                                       3
<PAGE>   4

                          VISTA ENERGY RESOURCES, INC.
                     CONSOLIDATED STATEMENTS OF OPERATIONS



<TABLE>
<CAPTION>
                                                             Three Months Ended                 Nine Months Ended
                                                                September 30,                     September 30,
                                                            1999             1998             1999             1998
                                                        ------------     ------------     ------------     ------------
                                                         (UNAUDITED)      (UNAUDITED)      (UNAUDITED)      (UNAUDITED)
<S>                                                     <C>              <C>              <C>              <C>
REVENUES:
   Oil and gas sales                                    $  4,371,641     $  1,927,397     $ 12,856,692     $  5,984,676
                                                        ------------     ------------     ------------     ------------
       Total revenues                                      4,371,641        1,927,397       12,856,692        5,984,676
COSTS AND EXPENSES:
        Lease Operating                                    1,795,863          838,347        4,655,601        2,777,877
        Exploration Costs                                     14,082           25,458           52,850           25,458
        Depreciation, depletion and amortization           1,381,387          267,575        3,593,750        1,229,601
        General and administrative                           512,743          563,976        1,480,879        1,184,641
        Amortization of Unit Option Awards                        --           21,326               --          214,303
                                                        ------------     ------------     ------------     ------------
            Total costs and expenses                       3,704,075        1,716,682        9,783,080        5,431,880
                                                        ------------     ------------     ------------     ------------
            Operating income                                 667,566          210,715        3,073,612          552,796
        Gain (loss) on sale of property                       77,112         (146,464)         147,141         (339,362)
        Interest income                                        3,195               --            8,172               --
        Interest expense                                  (1,012,315)        (356,162)      (3,047,674)      (1,070,123)
        Other income, net                                     37,898           20,616           50,512           60,907
                                                        ------------     ------------     ------------     ------------
NET INCOME (LOSS) BEFORE TAXES                              (226,544)        (271,295)         231,763         (795,782)
         Income tax expense (benefit):
           Current                                                --               --               --               --
            Deferred                                         (79,290)              --           81,117               --
            Pro Forma benefit (provision) for  taxes              --           94,953               --          278,524
                                                        ------------     ------------     ------------     ------------
NET INCOME (LOSS)                                       $   (147,254)    $   (176,342)    $    150,646     $   (517,258)
                                                        ============     ============     ============     ============
Earnings (loss) per share:
       Basic                                            $       (.01)    $       (.01)    $        .01     $       (.05)
                                                        ============     ============     ============     ============
       Diluted                                          $       (.01)    $       (.01)    $        .01     $       (.05)
                                                        ============     ============     ============     ============
Weighted Average Shares Outstanding - Basic               16,348,798       11,903,506       16,324,624       11,903,506
                                                        ============     ============     ============     ============
Weighted Average Shares Outstanding - Diluted             16,348,798       11,903,506       16,324,624       11,903,506
                                                        ============     ============     ============     ============
</TABLE>




              The accompanying notes are an integral part of these
                      consolidated financial statements.


                                       4
<PAGE>   5

                          VISTA ENERGY RESOURCES, INC.
                     CONSOLIDATED STATEMENTS OF CASH FLOWS


<TABLE>
<CAPTION>
                                                                           Nine Months Ended
                                                                             September 30,
                                                                          1999             1998
                                                                      ------------     ------------
                                                                       (UNAUDITED)     (UNAUDITED)
<S>                                                                   <C>              <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net income (loss)  before pro forma tax expense                     $    150,646     $   (795,782)
  Adjustments to reconcile net income (loss)
   before taxes to cash provided by
   operating activities:
   Depreciation, depletion and amortization                              3,506,328        1,229,601
    Amortization of deferred borrowing costs                                87,422
    Provision for income tax                                                81,117               --
    Amortization of unit option awards                                          --          214,303
    Other assets                                                          (451,046)        (444,426)
    (Gain) Loss  on sale of property                                      (147,141)         339,362
   Changes in working capital
      Decrease (increase) in accounts receivable                        (1,922,943)         253,189
      Decrease (increase) in other current assets                          (11,147)        (373,597)
      Decrease (increase) in accounts payable and accrued expenses       1,754,537           16,875
                                                                      ------------     ------------
      Net cash provided by (used in) operating activities                3,047,773          439,525
                                                                      ------------     ------------

CASH FLOWS FROM INVESTING ACTIVITIES:
  Additions to property and equipment                                   (5,265,215)      (2,427,927)
  Proceeds from sales of property and Equipment                            335,219          544,364
                                                                      ------------     ------------
         Net cash used in investing activities                          (4,929,996)      (1,883,563)
                                                                      ------------     ------------

CASH FLOWS FROM FINANCING ACTIVITIES:
  Payment of borrowings                                                 (1,017,154)              --
  Proceeds from issuance of debt                                         2,920,000        1,000,000
                                                                      ------------     ------------
         Net cash provided by financing activities                       1,902,846        1,000,000
                                                                      ------------     ------------

NET INCREASE (DECREASE) IN CASH AND CASH
  EQUIVALENTS                                                               20,623         (444,038)

CASH AND CASH EQUIVALENTS:
  Beginning of period                                                           --          527,129
                                                                      ------------     ------------
  End of period                                                       $     20,623     $     83,091
                                                                      ============     ============
</TABLE>



              The accompanying notes are an integral part of these
                       consolidated financial statements.



                                       5
<PAGE>   6



                          VISTA ENERGY RESOURCES, INC.
              NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS
                               SEPTEMBER 30, 1999
                                  (UNAUDITED)

1. ORGANIZATION:

Organization

         Vista Energy Resources, Inc. and its subsidiaries (collectively,
"Vista" or the "Company") is a Delaware corporation whose common stock is
listed and traded on the American Stock Exchange. The Company was incorporated
in May 1998 for the purpose of continuing and consolidating the operations of
Vista Resources Partners, L.P., a Texas limited partnership (the "Vista
Partnership"), and Midland Resources, Inc., a publicly traded Texas corporation
("Midland Resources"). The merger of the Vista Partnership and Midland
Resources (the "Midland Merger") was completed on October 28, 1998. The Company
is an independent oil and gas company engaged in the acquisition, exploration,
production and development of oil and natural gas primarily in the Permian
Basin of West Texas and Southeastern New Mexico and the onshore Gulf Coast
region of South Texas.

         Vista Resources I, Inc., a Texas corporation (the "General Partner"),
now a wholly-owned subsidiary of the Company, serves as the sole general
partner of the Vista Partnership. Vista Resources, Inc., a wholly owned
subsidiary of the Company ("Vista Resources"), currently serves as the operator
of properties in which the Company or its subsidiaries acquires or otherwise
owns operating working interests.

         On October 28, 1998, pursuant to the terms of an Exchange Agreement
dated June 15, 1998 (the "Exchange Agreement"), the Company acquired all of the
outstanding partnership interests of the Vista Partnership and all of the
outstanding shares of common stock of the General Partner in exchange for
shares of Common Stock of the Company (the "Conversion"). The Conversion was
accounted for as a transfer of assets and liabilities between affiliates under
common control and resulted in no change in carrying values of these assets and
liabilities. The Conversion and other transactions contemplated by the Exchange
Agreement were consummated immediately prior to the closing of the Midland
Merger. As a result of the Conversion and the Midland Merger, security holders
of Midland Resources acquired 4,470,123 shares or 27.3 percent of the
outstanding "Common Stock" of the Company, and security holders of the Vista
Partnership acquired 11,903,506 shares of Common Stock, or 72.7 percent.
Accordingly, the accompanying financial statements include the results of
operations of the Company and Midland Resources since October 28, 1998, and the
results of the Vista Partnership prior to that date.





                                       6
<PAGE>   7


2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:

Basis of Presentation

         In management's opinion, the accompanying consolidated financial
statements contain all adjustments necessary to present fairly the financial
position as of September 30, 1999 and related results of operations for the
three and nine months ended September 30, 1999 and 1998, and cash flows as
September 30, 1999 and 1998, respectively, of the Company and its wholly-owned
subsidiaries. All significant intercompany transactions and balances have been
eliminated in preparation of the consolidated financial statements.

         The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect the reported amounts of assets and liabilities and
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting period. Actual results could differ from those estimates.

         Certain information and footnote disclosures normally included in
financial statements prepared in accordance with generally accepted accounting
principles have been condensed or omitted in this Form 10-Q pursuant to the
rules and regulations of the Securities and Exchange Commission. These
consolidated financial statements should be read in conjunction with the audited
financial statements and notes thereto included in the Company's 1998 Form 10-K.

3. SIGNIFICANT ACQUISITIONS OF OIL AND GAS PROPERTIES AND OTHER ASSETS:

1999 Acquisitions

         The Company made no material asset acquisitions during the first nine
months of 1999.

1998 Acquisitions

         On October 28, 1998, the Company completed the Conversion and the
Midland Merger (see Note 1). The Company issued 4,470,123 shares of common
stock and 995,375 warrants with an exercise price of $4.00 to the Midland
Resources shareholders and warrant holders and assumed 261,800 Midland
Resources employee options (which expired without exercise in February 1999).
The Company also assumed 2,522,670 Midland Resources warrants to effect the
Midland Merger. In connection with the Midland Merger, the Company issued
11,903,506 shares of common stock and 8,563,028 warrants with an exercise price
of $4.00 to the Vista Partnership's existing partners so that the security
holders of the Vista Partnership would own 72.7 percent of the Company's
outstanding stock and warrants. The estimated value recorded for the
consideration paid to the Midland Resources shareholders was based on the
market value of the Midland Resources securities at the announcement of the
Midland Merger on May 26, 1998.




                                       7
<PAGE>   8

The allocation of the purchase price for the assets acquired and liabilities
assumed was as follows:

<TABLE>
<S>                                 <C>
         Working capital                  $     (895,132)
         Oil and gas properties           $   37,296,391
         Debt assumed                     $  (10,445,394)
         Deferred income taxes            $   (6,910,351)
                                          --------------
                  Purchase Price          $   19,045,514
                                          ==============
</TABLE>

         From the announcement of the Midland Merger in May 1998 to the closing
in October 1998, the trading price of the Midland Resources common stock
declined. In addition, oil prices decreased significantly from May 1998 to
December 1998. Accordingly, at December 31, 1998 the Company recorded a
significant impairment charge to the allocated value of oil and gas properties
recorded in purchase accounting for the Midland Merger. The total impairment
recognized related to the properties acquired from Midland Resources was
approximately $22.2 million.

         On December 18, 1998 (effective date of October 1, 1998), the Company
acquired working interests ranging from 65 percent to 85 percent in a group of
oil and gas producing leases from IP Petroleum Company, Inc. and certain of its
working interest partners. These leases are located primarily in the War-Wink
area of Ward and Winkler Counties, Texas, and the interests were acquired for a
purchase price of $19.1 million (the "IP Acquisition"). Collectively, the
Midland Merger and the IP Acquisition are referred to herein as the "1998
Acquisitions."

Pro Forma Condensed Statements of Operations

         The following unaudited Pro Forma Condensed Combined Statements of
Operations for the nine months ended September 30, 1998 give effect to the 1998
Acquisitions as if the acquisitions had been consummated at January 1, 1998.
The unaudited pro forma data is presented for illustrative purposes only and is
not necessarily indicative of the operating results that would have occurred
had the transactions been consummated at the dates indicated, nor are they
necessarily indicative of future operating results.

           Pro Forma Condensed Consolidated Statements of Operations
                                  (unaudited)

<TABLE>
<CAPTION>
                                 For the nine months ended September 30,
                                 ---------------------------------------
                                                  1998
                                              -------------
<S>                                           <C>
Total revenues                                $  13,349,358
Net income (loss)                                (1,111,429)
Basic Net income (loss)                                (.07)
Diluted Earnings per share                             (.07)
</TABLE>

                                       8
<PAGE>   9

4.  LONG-TERM DEBT:

         As of September 30, 1999, $52.6 million was outstanding under a $100
million revolving Credit Agreement dated December 18, 1998, and accompanying
note (the "Credit Facility") with BankBoston subject to a borrowing base which
is redetermined on a semi-annual basis. The borrowing base at September 30,
1999, was $55 million. The next scheduled borrowing base redetermination is
scheduled for February 28, 2000. Borrowings under the Credit Facility are to be
used for the acquisition and development of oil and gas properties and for
other Company purposes.

         The Company has two options with respect to interest rate elections on
borrowings under the Credit Facility. The Company may either elect an interest
rate equal to (i) the Alternate Base Rate plus the Applicable Margin ("Prime
Basis") or (ii) a Eurodollar rate (i.e., London Interbank Offered Rate) plus
the Applicable Margin ("LIBOR Basis"). The Applicable Margin (as defined in the
Credit Facility) will be adjusted for Borrowing Base usage. The LIBOR Basis
option provides for one-, two-, three-, six- and twelve-month interest
periods. At September 30, 1999, the effective interest rate on the amount
outstanding was 7.59 percent.

         Unless otherwise extended by BankBoston, the Credit Facility converts
to a three-year fully amortizing term loan at December 15, 2001.

         The obligations of the Company under the Credit Facility are secured
by a first lien deed of trust on the Company's interests in certain of its oil
and gas properties.

         The Credit Facility contains two financial covenants including a
minimum current ratio, including available borrowings, of 1:1 and an interest
coverage to EBITDA test (2.0 to 1.0 for the four-fiscal quarter period ending
December 31, 1998; 2.25 to 1.0 for the four-fiscal quarter period ending March
31, 1999; and 2.5 to 1.0 for each four-fiscal quarter period thereafter). The
Credit Facility also includes covenants which, among other things, restrict the
incurrence of additional indebtedness and the sale or acquisition of oil and
gas properties above certain levels without the consent of the lender.

         Effective as of December 23, 1997, the Company entered into an
interest rate swap accounted for as a hedge with any realized gains or losses
appropriately recorded as interest expense (See Note 7 for further discussion
of hedge accounting.). The swap consists of a $10 million notional amount of
indebtedness at a fixed swap rate of 6.02 percent three-month LIBOR for the
Company. The term of this swap ends on December 23, 1999. Effective as of
January 1, 1999, this interest rate swap was assigned to BankBoston. In
conjunction with such assignment the terms of the swap were modified to reduce
the fixed swap rate from 6.02 percent to 5.65 percent and to extend the term of
the swap until December 23, 2000, at the option of BankBoston.


                                       9
<PAGE>   10



5. COMMITMENTS AND CONTINGENCIES:

Litigation

         At December 31, 1998, the Company was a Defendant in a lawsuit filed
on July 31, 1995, styled Manna Oil & Gas, Inc., Dobbs Oil & Gas, Inc. v.
Midland Resources, Inc. , Miresco Inc., Midland Resources Operating Company,
Inc., Cause No. 40,677. The case involved disputes with a non-operating
interest owner concerning the operation of certain Gulf Coast properties
located in Copano Bay, Aransas County, Texas, wherein the Company owns a 68
percent working interest and is the operator of the properties. The lawsuit was
settled in February 1999 by the Company acquiring all of the interests of the
Plaintiffs in the subject properties for a net purchase price of $0.7 million.

         The Company and its subsidiaries are, from time to time, involved in
various other lawsuits and certain governmental proceedings arising in the
ordinary course of business.

6. EARNINGS PER SHARE:

         Effective December 31, 1997, the Company adopted the provisions of
SFAS 128, "Earnings Per Share", which prescribes standards for computing and
presenting earnings per share ("EPS") and supersedes APB Opinion 15, "Earnings
Per Share."

         The computation of basic and diluted earnings (loss) per share were
identical for the nine months ended September 30, 1999, and for the years ended
December 31, 1998 and 1997 due to the following:

         Options to purchase 261,800 shares of common stock were outstanding
         since October 28, 1998, but were not included in the computation of
         diluted EPS because the options' exercise price was greater than the
         average market price of the Common Stock. All outstanding options
         expired in February 1999.

         Warrants to purchase 12,081,073 shares of Common Stock were not
         included in the computation of EPS as they are antidilutive as a
         result of the Company's net loss for the year ended December 31, 1998.
         All of these warrants, 11,811,073 of which expire on November 1, 2002,
         with the remaining warrants expiring from March 1999 through June
         2002, were still outstanding at December 31, 1998.

         As the Conversion was not completed until October 28, 1998, there were
         no potentially dilutive equity securities outstanding at either
         December 31, 1997 and 1996.

         EPS has been calculated for all periods presented as if the Conversion
         had been completed on January 1, 1996.

                                      10
<PAGE>   11

7. PRICE RISK MANAGEMENT:

Commodity Price Hedging Instruments

         The Company periodically uses derivative financial instruments to
manage crude oil and natural gas price risk. These instruments qualify as
hedges under generally accepted accounting principles and are properly recorded
as adjustments to oil and gas sales in the consolidated statements of
operations. In order to qualify for hedge accounting, each financial instrument
must be initially designated as a hedge, must appropriately reduce the price
risk and must have correlation to the commodity being hedged. If an instrument
does not qualify as a hedge, then it is accounted for as a speculative
transaction. It is the Company's policy not to engage in speculative
transactions of this nature. The Company's realized gains and losses
attributable to its price risk management activities was ($1.4) million for the
first nine months of 1999 as compared to ($.5) million for the same period in
1998.

         Set forth below is the contract amount and material terms of all crude
oil hedging instruments held by the Company at September 30, 1999 (monthly
volumes are expressed in Bbls and all prices are expressed in the calendar
monthly average of daily NYMEX closing prices for Light Sweet Crude Oil):

<TABLE>
<CAPTION>
    TRADE DATE        TYPE TRANSACTION       MONTHLY VOLUME       PUT FLOOR PRICE     CALL CEILING PRICE            TERM
    ----------        ----------------       --------------       ---------------     ------------------     -----------------
<S>                   <C>                    <C>                  <C>                 <C>                    <C>
     12-11-98               Swap                 40,000             $14.20 Bbl            $14.20 Bbl         8-1-99 to 6-30-00
     04-19-99              Collar                20,000             $15.00 Bbl            $17.00 Bbl         1-1-00 to 6-30-00
     04-19-99              Collar                40,000             $15.00 Bbl            $16.85 Bbl         7-1-00 to 12-31-00
</TABLE>

         Set forth below is the contract amount and material terms of all NYMEX
natural gas hedging instruments held by the Company at September 30, 1999
(monthly volumes are expressed in MMBtus and prices are expressed in the
monthly NYMEX (Henry Hub) closing price for natural gas):

<TABLE>
<CAPTION>
    TRADE DATE         TYPE TRANSACTION       MONTHLY VOLUME       PUT FLOOR PRICE      CALL CEILING PRICE           TERM
    ----------         ----------------       --------------       ---------------      ------------------    ------------------
<S>                    <C>                    <C>                  <C>                  <C>                   <C>
     08-20-98               Collar                40,000              $2.25 Mcf             $2.42 Mcf         1-1-99 to 12-31-99
     11-12-98               Collar                50,000              $2.25 Mcf             $2.51 Mcf         1-1-99 to 12-31-99
     08-20-98               Collar                40,000              $2.17 Mcf             $2.55 Mcf         1-1-99 to 12-31-99
     12-28-98                Swap                 50,000              $2.01 Mcf             $2.01 Mcf         1-1-99 to 12-31-99
     01-12-98                Swap                120,000              $2.12 Mcf             $2.12 Mcf         1-1-00 to 12-31-00
     02-08-99                Swap                120,000              $2.35 Mcf             $2.35 Mcf         1-1-01 to 12-31-01
</TABLE>

         The Company also hedges from time to time the basis for its natural
gas production which depends upon the location of its gas production. Such
basis hedges are immaterial to the financial performance of the Company.

Interest Rate Swap Agreement

         Effective as of December 23, 1997, the Company entered into an
interest rate swap accounted for as a hedge with any realized gains or losses
appropriately recorded as interest




                                      11
<PAGE>   12

expense. The swap consists of a $10 million notional amount of indebtedness at
a fixed swap rate of 6.02 percent based on the three-month LIBOR for the
Company. The term of this swap ends on December 23, 1999. Effective as of
January 1, 1999, this interest rate swap was assigned to BankBoston. In
conjunction with such assignment the terms of the swap were modified to reduce
the fixed swap rate from 6.02 percent to 5.65 percent and to extend the term of
the swap until December 23, 2000, at the option of BankBoston.

8. SUBSEQUENT EVENT:

         On October 8, 1999, the Company and Prize Energy Corp., a Delaware
corporation ("Prize"), entered into a definitive agreement to merge the two
companies. The transaction will create a mid-size independent oil and gas
company with assets valued in excess of $450 million. The combined company's
focused growth strategy is concentrated on the acquisition and exploitation of
oil and gas properties in its core operating areas of the Permian Basin of West
Texas and Southeastern New Mexico, onshore Gulf Coast area of Texas and
Louisiana and the Mid-Continent area of Western Oklahoma and the Texas
panhandle.

         Under the terms and conditions of the Agreement and Plan of Merger
between the Company and Prize, Prize would become a wholly-owned subsidiary of
the Company in exchange for 58.2 million shares of common stock of the Company
(with such number of shares being subject to adjustment in order to reflect a
proposed reverse stock split) and 27.7 million shares of to be created Series A
6% Convertible Preferred Stock of the Company (with such number of shares being
subject to adjustment in order to reflect a proposed reverse stock split). The
Company's outstanding warrants will remain outstanding in accordance with their
terms. The transaction is to be structured as a reorganization for tax purposes
and will result in the current holders of common stock of the Company owning
approximately 16% of the outstanding common stock of the combined company and
the holders of common stock and preferred stock of Prize collectively owning
(on a fully converted basis) approximately 84% of the outstanding common stock
of the combined company upon completion of the merger.

         The combined company will be headquartered in the Dallas, Texas area
with operating offices in Midland and Victoria, Texas and Elmore City,
Oklahoma. The combined company will have a capital structure consisting of
approximately 74.6 million shares of common stock outstanding (with such number
of shares being subject to adjustment in order to reflect a proposed reverse
stock split), approximately $30 million of convertible preferred securities and
approximately $195 million of net long-term debt.





                                      12
<PAGE>   13

ITEM 2.       MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
              RESULTS OF OPERATIONS

FORWARD LOOKING STATEMENTS

          Certain information included in this quarterly report on Form 10-Q
and other materials filed by the Company with the SEC contain forward-looking
statements that involve risks and uncertainties that could cause actual results
to differ from projected results. Such statements address activities, events or
developments that the Company expects, believes, projects, intends or
anticipates will or may occur, including such matters as future capital,
development and exploration expenditures (including the amount and nature
thereof), drilling of wells, reserve estimates (including estimates of future
net revenues associated with such reserves and the present value of such future
net revenues), future production of oil and natural gas, future sales prices
for oil and gas production, business strategies, expansion and acquisition,
obtaining financial or industry partners for prospect or program development,
or marketing of oil and natural gas. Factors that could cause actual results to
differ materially are described, among other places, in this 10-Q and under the
caption "Results of Operations." Without limiting the Cautionary Disclosures so
described, Cautionary Disclosures include, among others: general economic
conditions, the market price of oil and natural gas, the risks associated with
exploration, the Company's ability to find, acquire, market, develop and
produce new properties, operating hazards inherent to the oil and natural gas
business, uncertainties in the estimation of proved reserves and in the
projection of future rates of production and timing of development
expenditures, the strength and financial resources of the Company's
competitors, the Company's ability to find and retain skilled personnel,
climatic conditions, labor relations, availability and cost of material and
equipment, environmental risks, the results of financing efforts, and
regulatory developments. All written and oral forward-looking statements
attributable to the Company or persons acting on its behalf are expressly
qualified in their entirety by the Cautionary Disclosures. The Company
disclaims any obligation to update or revise any forward-looking statement to
reflect events or circumstances occurring hereafter or to reflect the
occurrence of anticipated or unanticipated events.

THE FORMATION OF VISTA

         Vista Energy Resources, Inc. (the "Company") is a Delaware corporation
whose common stock is listed and traded on the American Stock Exchange. The
company was formed in May 1998 for the purpose of merging Vista Resources
Partners, L.P. , a Texas limited partnership (the "Vista Partnership"), and
Midland Resources, Inc., a publicly traded Texas corporation ("Midland
Resources"). Such merger occurred on October 28, 1998 (the "Midland Merger").
The Company is an oil and gas exploration and production company with ownership
interests in oil and gas properties located principally in the Permian Basin of
West Texas and Southeastern New Mexico and the onshore Gulf Coast region of
Texas.

         In accordance with the provisions of Accounting Principles Board
("APB") No. 16 Business Combinations, the merger of the Vista Partnership and
Midland Resources was




                                      13
<PAGE>   14

accounted for as a purchase by the Company (formerly the Vista Partnership). As
a result, the historical financial statements for the Company are those of the
Vista Partnership.

FINANCIAL PERFORMANCE

          The Company reported a net income or (loss) of ($.1) million ($ .01
per share) and $.2 million ($ .01 per share) for the three and nine months
ended September 30, 1999, respectively, as compared to a net loss of ($ .2)
million ($ .01 per share) and ($ .5) million ($ .05 per share) for the same
periods in 1998. As discussed more fully in "Results of Operations" below, the
Company's financial performance for the three months ended September 30, 1999,
was negatively impacted by the following items: (i) increase in gross
production costs due to the addition of properties acquired in the 1998
Acquisitions (hereinafter defined); and (ii) an increase in interest expense as
a result of the additional indebtedness incurred in respect of the 1998
Acquisitions.

         Net cash provided by operating activities was $ 3.0 million during
nine months ended September 30, 1999, as compared to net cash provided by
operating activities of $ .4 million for the same period in 1998. This increase
was primarily attributable to increases in production from the properties
acquired in the 1998 Acquisitions and production increases from the Company's
success in its 1998 and 1999 drilling and recompletion program offset by
increased gross production costs and interest expense as a result of the
additional properties acquired and indebtedness incurred in respect of the 1998
Acquisitions.

         The Company strives to maintain its outstanding indebtedness at a
moderate level in order to provide sufficient financial flexibility to fund
future opportunities. The Company's total book capitalization at September 30,
1999, was $58.1 million, consisting of total long-term debt of $52.6 million
and owners' equity of $5.5 million. Debt as a percentage of total book
capitalization was 90 percent at September 30, 1999, which was essentially the
same as at December 31, 1998.

DRILLING RESULTS

         During the first nine months of 1999, the Company has continued its
emphasis on development, exploration and production activities, with a primary
focus on the exploitation of its current portfolio of drilling locations.
During the first nine months of 1999, the Company participated in the drilling
and completion of 11 gross development wells and four gross exploration wells.
None of these wells were in progress at December 31, 1998. Of the 15 wells
drilled during the nine months ended September 30, 1999, 13 were completed
successfully which resulted in a 87 percent success rate. In addition to the
wells completed in the first nine months of 1999, the Company had four wells in
progress at September 30, 1999.




                                      14
<PAGE>   15

ACQUISITION ACTIVITIES

         1999 Acquisitions - Although various acquisition candidates were
evaluated during the first nine months of 1999, no material asset acquisitions
were made during such time period.

         On October 8, 1999, the Company and Prize Energy Corp., a Delaware
corporation ("Prize"), entered into a definitive agreement to merge the two
companies. The transaction will create a mid-size independent oil and gas
company with assets valued in excess of $450 million. The combined company's
focused growth strategy is concentrated on the acquisition and exploitation of
oil and gas properties in its core operating areas of the Permian Basin of West
Texas and Southeastern New Mexico, onshore Gulf Coast area of Texas and
Louisiana and the Mid-Continent area of Western Oklahoma and the Texas
panhandle.

         Under the terms and conditions of the Agreement and Plan of Merger
between the Company and Prize, Prize would become a wholly-owned subsidiary of
the Company in exchange for 58.2 million shares of common stock of the Company
(with such number of shares being subject to adjustment in order to reflect a
proposed reverse stock split) and 27.7 million shares of to be created Series A
6% Convertible Preferred Stock of the Company (with such number of shares being
subject to adjustment in order to reflect a proposed reverse stock split). The
Company's outstanding warrants will remain outstanding in accordance with their
terms. The transaction is to be structured as a reorganization for tax purposes
and will result in the current holders of common stock of the Company owning
approximately 16% of the outstanding common stock of the combined company and
the holders of common stock and preferred stock of Prize collectively owning
(on a fully converted basis) approximately 84% of the outstanding common stock
of the combined company upon completion of the merger.

         The combined company will be headquartered in the Dallas, Texas area
with operating offices in Midland and Victoria, Texas and Elmore City,
Oklahoma. The combined company will have a capital structure consisting of
approximately 74.6 million shares of common stock outstanding (with such number
of shares being subject to adjustment in order to reflect a proposed reverse
stock split), approximately $30 million of convertible preferred securities and
approximately $195 million of net long-term debt. (See Part II, Item 5 "Other
Information").

         1998 Acquisitions - On October 28, 1998, the Midland Merger between
the Vista Partnership and Midland Resources was completed resulting in the
formation of the Company. As a result of the Midland Merger, Midland Resources'
security holders acquired 27.3 percent of the outstanding Common Stock of the
Company and security holders of the Vista Partnership acquired the remaining
72.7 percent of the outstanding Common Stock of the Company. In addition, upon
consummation of the Midland Merger, the Common Stock of Vista, the newly merged
company, became publicly traded on the American Stock Exchange effective
October 29, 1998.



                                      15
<PAGE>   16

         Effective as of October 1, 1998, the Company acquired working
interests ranging from 65 percent to 85 percent in a group of oil and gas
producing leases from IP Petroleum Company, Inc. and certain of its working
interest partners (the "IP Acquisition"). These leases are located primarily in
the War-Wink area of Ward and Winkler Counties, Texas, and the interests were
acquired for a purchase price of $19.1 million. The IP Acquisition closed on
December 18, 1998. The Midland Merger and the IP Acquisition are sometimes
collectively referred to herein as the "1998 Acquisitions."

RESULTS OF OPERATIONS

         Oil and Gas Production.

<TABLE>
<CAPTION>
                                                 THREE MONTHS ENDED                NINE MONTHS ENDED
                                                    SEPTEMBER 30,                   SEPTEMBER 30,
                                             ----------------------------    ----------------------------
                                                 1999            1998            1999            1998
                                             ------------    ------------    ------------    ------------
<S>                                          <C>             <C>             <C>             <C>
Revenues                                     $  4,371,641    $  1,927,397    $ 12,856,692    $  5,984,676
Costs and expenses:
  Production costs                              1,795,863         838,347       4,655,601       2,777,877
  Depletion                                     1,381,387         267,575       3,593,750       1,229,601
  Exploration costs                                14,082          25,458          52,850          25,458
                                             ------------    ------------    ------------    ------------
    Total costs and expenses                    3,191,332       1,131,380       8,302,201       4,032,936
                                             ------------    ------------    ------------    ------------
  Operating profit (excluding general and
     administrative expenses and
     income taxes)                           $  1,180,309    $    796,017    $  4,554,491    $  1,951,740
                                             ============    ============    ============    ============

Production:
  Oil (Bbls)                                      237,093         106,461         687,731         342,234
  Gas (Mcf)                                       737,625         223,356       2,243,836         701,346
    Total (BOE)                                   360,031         143,687       1,061,704         459,125
Average Daily Production:
  Oil (Bbls)                                        2,577           1,157           2,519           1,254
  Gas (Mcf)                                         8,018           2,427           8,219           2,569
                                             ------------    ------------    ------------    ------------
    Total (BOE)                                     3,913           1,562           3,889           1,682
Average Oil Price (Per Bbl)                  $      13.43    $      11.50    $      12.84    $      13.50
Average Gas Price (Per Mcf)                  $       1.61    $       1.79    $       1.80    $       1.94
Costs (Per BOE):
  Lease operating expense                    $       4.10    $       4.86    $       3.66    $       5.03
  Production taxes                           $        .89    $        .98    $        .73    $       1.02
                                             ------------    ------------    ------------    ------------
    Total production costs                   $       4.99    $       5.84    $       4.39    $       6.05
  Depletion                                  $       3.84    $       1.86    $       3.38    $       2.68
</TABLE>


         Oil and Gas Revenues. Revenues from oil and gas operations totaled
$4.3 million and $12.9 million for the three and nine months ended September
30, 1999, compared to $2.0 and $6.0 million for the same periods in 1998,
representing an increase of 115 percent and 115 percent, respectively. The
increase is primarily attributable to the 1998 Acquisitions and increases in
production due to the Company's successful exploitation activities in 1998 and
1999, offset by decreased average prices being received for the nine month
period for both oil and gas production (as a result of the oil and gas price
hedges the Company had in place during the first nine months of 1999). The
average oil prices received (inclusive of hedging activities) for the three and
nine months ended September 30, 1999, was $13.43 and $12.84, respectively,
compared to $11.50 and $13.50 for the three and nine months ended September 30,
1998, while the average gas price received (inclusive of hedging activities)
was $1.61 and $1.80 for the three and nine months ended September 30, 1999,
respectively, compared to $1.79 and $1.94 for the same periods in 1998.



                                      16
<PAGE>   17

         Average daily oil production increased 123 percent and 101 percent to
2,577 Bbls and 2,519 Bbls for the three and nine months of 1999 from 1,157 Bbls
and 1,254 Bbls for the same period of 1998; and average daily gas production
increased 231 percent and 220 percent to 8,018 Mcf and 8,219 Mcf from 2,427 Mcf
and 2,569 Mcf for the same period.

         Hedging Activities. The oil and gas prices that the Company reports is
based on the actual prices received for the commodities adjusted for the
results of any of the Company's hedging activities. The Company periodically
enters into commodity derivative contracts (i.e., swaps and collars) in order
to (i) reduce the effect of the volatility of price changes on the commodities
the Company produces and sells; (ii) support the Company's annual capital
budgeting and expenditure plans; and (iii) lock in prices to protect the
economics related to certain capital projects. Set forth below is the contract
amount and material terms of all crude oil hedging instruments held by the
Company at September 30, 1999 (monthly volumes are expressed in Bbls and all
prices are expressed in the calendar monthly average of daily NYMEX closing
prices for Light Sweet Crude Oil):


<TABLE>
<CAPTION>
                                                                                                                   UNREALIZED
                                                                                                                      GAIN
                                                                                                                    (LOSS) AT
    TRADE DATE     TYPE TRANSACTION     MONTHLY VOLUME  PUT FLOOR PRICE  CALL CEILING PRICE           TERM       SEPTEMBER 30,1999
    ----------     ----------------     --------------  ---------------  ------------------    ----------------- -----------------
<S>                <C>                  <C>             <C>              <C>                  <C>                    <C>
     12-11-98             Swap              40,000        $14.20 Bbl        $14.20 Bbl         8-1-99 to 6-30-00     2,890,724
     04-19-99             Swap              20,000        $15.00 Bbl        $17.00 Bbl         1-1-00 to 6-30-00       566,380
     04-19-99            Collar             40,000        $15.00 Bbl        $16.85 Bbl         7-1-00 to 12-31-00      735,433
</TABLE>

         Set forth below is the contract amount and material terms of all NYMEX
natural gas hedging instruments held by the Company at September 30, 1999
(monthly volumes are expressed in MMBtus and prices are expressed in the
monthly NYMEX (Henry Hub) closing price for natural gas):

<TABLE>
<CAPTION>
                                                                                                                     UNREALIZED
                                                                                                                       GAIN
                                                                                                                     (LOSS) AT
    TRADE DATE     TYPE TRANSACTION     MONTHLY VOLUME  PUT FLOOR PRICE  CALL CEILING PRICE           TERM       SEPTEMBER 30, 1999
    ----------     ----------------     --------------  ---------------  ------------------    ----------------- ------------------
<S>                <C>                  <C>             <C>              <C>                  <C>                      <C>
     08-20-98           Collar              40,000         $2.25 Mcf         $2.42 Mcf         1-1-99 to 12-31-99       37,620
     11-12-98           Collar              50,000         $2.25 Mcf         $2.51 Mcf         1-1-99 to 12-31-99       42,830
     08-20-98           Collar              40,000         $2.17 Mcf         $2.55 Mcf         1-1-99 to 12-31-99       39,011
     12-28-98            Swap               50,000         $2.01 Mcf         $2.01 Mcf         1-1-99 to 12-31-99       91,400
     01-12-98            Swap              120,000         $2.12 Mcf         $2.12 Mcf         1-1-00 to 12-31-00      796,000
     02-08-99            Swap              120,000         $2.35 Mcf         $2.35 Mcf         1-1-01 to 12-31-01      328,480
</TABLE>


         The Company also hedges from time to time the basis for its natural
gas production which depends upon the location of its gas production. Such
basis hedges are immaterial to the financial performance of the Company.

         Production Costs. Total production costs (inclusive of all lease
operating expenses and production taxes) per BOE decreased 15 percent and 28
percent to $4.99 and $4.39 during the three and nine months ended September 30,
1999, respectively, as compared to production costs per BOE of $5.84 and $6.05
during the same period of 1998. These reductions are primarily due to the
Company's continued and concentrated efforts to evaluate and reduce all
operating costs and the addition of higher margin properties acquired by the
Company in the 1998 Acquisitions.



                                      17
<PAGE>   18

         Exploration Costs. Exploration costs (which includes abandonments, dry
hole costs, and geological and geophysical costs) were $14,082 and $52,850
during the three and nine months of 1999 as compared to $25,458 and $25,458 for
the same periods in 1998 because the Company incurred certain geological and
geophysical costs during the first nine months of 1999.

         General and Administrative Expense. General and administrative expense
was $.5 million and $1.5 million for the three and nine months ended September
30, 1999, as compared to $.6 million and $1.2 million for the same period ended
September 30, 1998, representing a decrease of 16 percent and an increase of 25
percent for the same periods, respectively. Such increase was primarily due to
the costs associated with the hiring of additional employees in late 1998 and
early 1999 as the Company's business has grown and due to the Company becoming
a publicly traded company in late 1998. However, on a BOE basis, the Company's
general and administrative expense was $1.43 and $1.40 per BOE for the three
and nine months ended September 30, 1998, compared to $3.93 and $2.58 per BOE
for the three and nine months ended September 30, 1999.

         Interest Expense. Interest expense was $1.0 million and $3.0 million
and $.4 million and $1.1 million for the three and nine months ended September
30, 1999 and 1998, respectively. This increase is primarily due to additional
borrowings made in connection with the 1998 Acquisitions.

         Depletion, Depreciation and Amortization Expense. Depletion expense
per BOE increased to $3.84 and $3.38 during the three and nine months ended
September 30, 1999, as compared to $1.86 and $2.68 during the same period in
1998. The increase in depletion expense per BOE is primarily related to the
additional properties acquired in the 1998 Acquisitions.

CAPITAL COMMITMENTS, CAPITAL RESOURCES AND LIQUIDITY

         Capital Commitments. The Company's primary needs for cash are for
acquisitions, development and exploration of oil and gas properties, repayment
of principal and interest on outstanding indebtedness and working capital
obligations. The Company's cash expenditures during the first nine months of
1999 for additions to oil and gas properties totaled $ 5.3 million. This amount
includes $ 1.0 million for the acquisition of properties and $ 4.3 million for
development and exploratory drilling.

         The Company's 1999 capital expenditure drilling budget has been
approved at an amount up to $11.1 million. Pursuant to this budget $9.3 million
has been allocated to exploitation and development activities and $1.8 million
to exploration activities. The Company does not budget for oil and gas property
acquisitions as they are made on a case by case basis as opportunities arise.
The 1999 budget reflects the Company's plans to drill and/or recomplete
approximately 25 oil and gas wells in 1999. The Company currently expects to
fund its 1999 capital expenditure budget primarily with internally generated
cash flow, borrowings under its bank credit facility and proceeds from the sale
of non-strategic assets.



                                      18
<PAGE>   19

         Capital Resources. The Company's primary capital resources are net
cash provided by operating activities, borrowings under its bank credit
facility and proceeds from the sale of non-strategic assets.

Financing Activities.

         As of September 30, 1999, $52.6 million was outstanding under a $100
million revolving Credit Agreement dated December 18, 1998, and accompanying
note (the "Credit Facility") with BankBoston subject to a borrowing base which
is redetermined on a semi-annual basis. The borrowing base at September 30,
1999, was $55 million. The next scheduled borrowing base redetermination is
scheduled for February 28, 2000. Borrowings under the Credit Facility are to be
used for the acquisition and development of oil and gas properties and for
other Company purposes.

         The Company has two options with respect to interest rate elections on
borrowings under the Credit Facility. The Company may either elect an interest
rate equal to (i) the Alternate Base Rate plus the Applicable Margin ("Prime
Basis") or (ii) a Eurodollar rate (i.e., London Interbank Offered Rate) plus
the Applicable Margin ("LIBOR Basis"). The Applicable Margin (as defined in the
Credit Facility) will be adjusted for Borrowing Base usage. The LIBOR Basis
option provides for one-, two-, three-, six- and twelve-month interest
periods. At September 30, 1999, the effective interest rate on the amount
outstanding was 7.59 percent.

         Unless otherwise extended by BankBoston, the Credit Facility converts
to a three-year fully amortizing term loan at December 15, 2001.

         The obligations of the Company under the Credit Facility are secured
by a first lien deed of trust on the Company's interests in certain of its oil
and gas properties.

         The Credit Facility contains two financial covenants including a
minimum current ratio, including available borrowings, of 1:1 and an interest
coverage to EBITDA test (2.0 to 1.0 for the four-fiscal quarter period ending
December 31, 1998; 2.25 to 1.0 for the four-fiscal quarter period ending March
31, 1999; and 2.5 to 1.0 for each four-fiscal quarter period thereafter). The
Credit Facility also includes covenants which, among other things, restrict the
incurrence of additional indebtedness and the sale or acquisition of oil and
gas properties above certain levels without the consent of the lender.

         Effective as of December 23, 1997, the Company entered into an
interest rate swap accounted for as a hedge with any realized gains or losses
appropriately recorded as interest expense (See Note 7 for further discussion
of hedge accounting.). The swap consists of a $10 million notional amount of
indebtedness at a fixed swap rate of 6.02 percent three-month LIBOR for the
Company. The term of this swap ends on December 23, 1999. Effective as of
January 1, 1999, this interest rate swap was assigned to BankBoston. In
conjunction with such assignment the terms of the swap were modified to reduce
the fixed swap rate from 6.02 percent to 5.65 percent and to extend the term of
the swap until December 23, 2000, at the option of BankBoston.



                                      19
<PAGE>   20

         Liquidity. At September 30, 1999, the Company had cash of $.02 million
on hand compared to $0 at December 31, 1998. The Company's ratio of current
assets (excluding borrowing base availability which is included, however, for
covenant purposes under the terms of the Company's Credit Facility) to current
liabilities was .95:1 at September 30, 1999 and .86:1 at December 31, 1998.

         Year 2000 Readiness Disclosure. "Year 2000," or the ability of
computer systems to process dates with years beyond 1999, affects almost all
companies and organizations. Computer systems that are not Year 2000 compliant
by January 1, 2000 may cause material adverse effects to companies and
organizations that rely upon those systems. Continuity of the Company's
operations in January 2000 will not only depend upon Year 2000 compliance of
the Company's computer systems and computer-controlled equipment, but also
compliance of computer systems and computer-controlled equipment of third
parties. These third parties include oil and natural gas purchasers and
significant service providers such as electric utility companies and natural
gas plant, pipeline and gathering system operators.

         The Company is in the process of reviewing its computer systems and
computer-controlled field equipment and making the necessary modifications for
Year 2000 compliance. The Company has completed modifications and testing of
its primary accounting and land computer programs. The remaining computer
systems have been inventoried and assessed.

         Based on its review, remediation efforts and the results of testing to
date, the Company does not believe that timely modification of its computer
systems and computer-controlled equipment for Year 2000 compliance represents a
material risk to the Company. The Company estimates that total costs related to
Year 2000 compliance efforts will be less than $10,000, of which approximately
$3,600 has been incurred and expensed through September 30, 1999.

         Despite efforts to assure that such third parties are Year 2000
compliant, the Company cannot provide assurance that all significant third
parties will achieve compliance in a timely manner. A third party's failure to
achieve Year 2000 compliance could have a material adverse effect on the
Company's operations and cash flow. The potential effect of Year 2000
non-compliance by third parties is currently unknown.

         The Company has developed appropriate contingency plans in the event
it becomes aware of potential problems resulting from failure of the Company's
or of significant third party computer systems on January 1, 2000. These
contingency plans include installing backup computer systems or equipment,
temporarily replacing systems or equipment with manual processes, and
identifying alternative suppliers, service companies and purchasers.

         The failure to correct a material Year 2000 problem could result in an
interruption in, or failure of, certain normal business activities or
operations. Due to the general uncertainty inherent in the Year 2000 problem,
resulting in part from the inability to ensure readiness of third parties, the
Year 2000 compliance issue could have a material adverse impact on the
Company's results of operations and financial condition.




                                      20
<PAGE>   21

                          PART II - OTHER INFORMATION

    ITEM 1.       LEGAL PROCEEDINGS

         None

    ITEM 2.       CHANGES IN SECURITIES

         None

    ITEM 3.       DEFAULTS UPON SENIOR SECURITIES

         None

    ITEM 4.       SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

         None

    ITEM 5.       OTHER INFORMATION

         On October 8, 1999, the Company and Prize Energy Corp., a Delaware
corporation ("Prize"), entered into a definitive agreement to merge the two
companies. The transaction will create a mid-size independent oil and gas
company with assets valued in excess of $450 million. The combined company's
focused growth strategy is concentrated on the acquisition and exploitation of
oil and gas properties in its core operating areas of the Permian Basin of West
Texas and Southeastern New Mexico, onshore Gulf Coast area of Texas and
Louisiana and the Mid-Continent area of Western Oklahoma and the Texas
panhandle.

         Under the terms and conditions of the Agreement and Plan of Merger
between the Company and Prize, Prize would become a wholly-owned subsidiary of
the Company in exchange for 58.2 million shares of common stock of the Company
(with such number of shares being subject to adjustment in order to reflect a
proposed reverse stock split) and 27.7 million shares of to be created Series A
6% Convertible Preferred Stock of the Company (with such number of shares being
subject to adjustment in order to reflect a proposed reverse stock split). The
Company's outstanding warrants will remain outstanding in accordance with their
terms. The transaction is to be structured as a reorganization for tax purposes
and will result in the current holders of common stock of the Company owning
approximately 16% of the outstanding common stock of the combined company and
the holders of common stock and preferred stock of Prize collectively owning
(on a fully converted basis) approximately 84% of the outstanding common stock
of the combined company upon completion of the merger.

         Dain Rauscher Wessels is serving as the financial advisor to the
Special Committee of the Company's board of directors and has rendered its
opinion to the Company's board of directors




                                      21
<PAGE>   22

with respect to the fairness, from a financial point of view, of the merger
consideration to be issued by the Company. The Company's and Prize's respective
boards of directors unanimously approved the proposed merger. Also, the merger
is subject to approval by a majority vote of the outstanding shares of both
companies as well as other customary closing conditions. The Company intends to
file a registration statement covering the securities to be issued in the
merger with the Securities and Exchange Commission as soon as practicable.
After such registration statement is declared effective, a prospectus, which
will also serve as the proxy statement in connection with the merger, will be
distributed to the stockholders of the Company and Prize. The offering of
securities pursuant to the proposed merger will be made only by means of such
prospectus/proxy statement. Completion of the merger is anticipated to occur in
the fourth quarter of 1999. The combined company is expected to be called Prize
Energy Corp. and is expected to trade on the American Stock Exchange under the
ticker symbol of PRZ.

         The combined company will be headquartered in the Dallas, Texas area
with operating offices in Midland and Victoria, Texas and Elmore City,
Oklahoma. The combined company will have a capital structure consisting of
approximately 74.6 million shares of common stock outstanding (with such number
of shares being subject to adjustment in order to reflect a proposed reverse
stock split), approximately $30 million of convertible preferred securities and
approximately $195 million of net long-term debt.

         The executive management team of Prize will serve as the executive
management team of the combined company. Philip B. Smith will be Chairman and
Chief Executive Officer and Lon C. Kile will be President and Chief Operating
Officer of the combined company.

    ITEM 6.       EXHIBITS AND REPORTS ON FORM 8-K

(a)      *2.1     Agreement and Plan of Merger dated as of October 8,
                  1999, among Vista Energy Resources, Inc., PEC Acquisition
                  Corp. and Prize Energy Corp.

         10.1     Vista Energy Resources, Inc. Severance Benefit Plan,
                  Effective October 8, 1999

         10.2     Consulting and Termination Agreement dated as of October 8,
                  1999, by and among Prize Energy Corp., Vista Energy
                  Resources, Inc. and C. Randall Hill

         10.3     Consulting and Termination Agreement dated as of October 8,
                  1999, by and among Prize Energy Corp., Vista Energy
                  Resources, Inc. and Steven D. Gray

         10.4     Consulting and Termination Agreement dated as of October 8,
                  1999, by and among Prize Energy Corp., Vista Energy
                  Resources, Inc. and R. Cory Richards

         27.1     Financial Data Schedule

(b)      Reports on Form 8-K:

         The Company filed a Current Report on Form 8-K dated October 15, 1999
         regarding its proposed merger with Prize Energy Corp.

------------------------

* Included in the Registrant's Current Report on Form 8-K dated October 15,
1999 regarding its proposed merger with Prize Energy Corp. and incorporated
herein by reference.


                                      22
<PAGE>   23



                                   SIGNATURES

    Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this Report to be signed on its behalf by the
undersigned thereunto duly authorized.



                                    VISTA ENERGY RESOURCES, INC.



    Date: November 15, 1999         By: /s/ C. RANDALL HILL
                                       ----------------------------------
                                       C. Randall Hill,
                                       Chairman, Chief Executive Officer,
                                       and Chief Financial Officer
                                       (Principal Accounting Officer and
                                       Duly Authorized Officer)


                                      23
<PAGE>   24


                               INDEX TO EXHIBITS


<TABLE>
<CAPTION>
EXHIBIT
NUMBER              DESCRIPTION
------              -----------
<S>               <C>

         *2.1     Agreement and Plan of Merger dated as of October 8,
                  1999, among Vista Energy Resources, Inc., PEC Acquisition
                  Corp. and Prize Energy Corp.

         10.1     Vista Energy Resources, Inc. Severance Benefit Plan,
                  Effective October 8, 1999

         10.2     Consulting and Termination Agreement dated as of October 8,
                  1999, by and among Prize Energy Corp., Vista Energy
                  Resources, Inc. and C. Randall Hill

         10.3     Consulting and Termination Agreement dated as of October 8,
                  1999, by and among Prize Energy Corp., Vista Energy
                  Resources, Inc. and Steven D. Gray

         10.4     Consulting and Termination Agreement dated as of October 8,
                  1999, by and among Prize Energy Corp., Vista Energy
                  Resources, Inc. and R. Cory Richards

         27.1     Financial Data Schedule
</TABLE>