# Frank Klaus

Frank Klaus (December 30, 1887, in Turtle Creek, Pennsylvania – February 8, 1948) was an American boxer from 1904 to 1918. Known as the Braddock Bearcat, Klaus claimed the vacant World Middleweight Championship in 1913 and was elected to the Ring Boxing Hall of Fame in 1974.
Gifted with a strong punch, he lost exceptionally few fights in his nine-year career, and was knocked out only once. Nat Fleischer ranked Klaus sixth as the All-Time Middleweight. His manager was George Engel.

## Early life and career

Frank Klaus was born on December 30, 1887, to German-American parents in Turtle Creek, Pennsylvania, near Pittsburgh. He worked as a young man at the Westinghouse Machine Shop, and also mined coal with his father.
He started boxing training early and after winning an amateur tournament at East Pittsburgh's Wilmerding Athletic Club was recognized to have boxing promise by local boxing mentor George Engel. He began his amateur career as early as 1904, and in February 1905 had three round wins on points in Pittsburgh against Frank Walton, and James Harris.
On October 18, 1911, Klaus defeated the great contender Leo Houck in a newspaper win by both the Philadelphia Item and the Philadelphia Record. During his career, the Pennsylvania-born middleweight fought some of the greatest welter, middle, and light heavyweights of his era, including Jack Dillon, Battling Levinsky, Mike Gibbons, Harry Greb, and Al McCoy.

## Claiming and defending the World Middleweight Title

Klaus claimed the World Middleweight Title a few years after it became vacant upon the death of Stanley Ketchel in October 1910. Several contenders competed for the title. Accounts vary as to when Klaus was officially champion, but Klaus himself first claimed the title after defeating Sailor Ed Petrosky in a 20-round points decision in San Francisco on February 22, 1912. His victories over Jack Dillon, and later fellow claimant Georges Carpentier and former champion Billy Papke in France, cemented his claim to the title. He was officially recognized as champion by sanctioning bodies on March 5, 1913.
In his historic title bout against Georges Carpentier on June 24, 1912, in Dieppe, France, Klaus won on a nineteenth round disqualification when Carpentier's manager entered the ring to protest his boxer being elbowed repeatedly by Klaus. Carpentier's manager tried to pull his fighter from the ring by his waist, but the boxer's second had already thrown in the towel.
On September 9, 1912, Klaus defeated Marcel Moreau in Savoie, France as the result of a low blow foul in the fourth of fifteen rounds. Moureau had held the French Middleweight Title in May 1908.

### Defeating Billy Papke for the Middleweight Title

In a title fight that led to world title recognition, Klaus defeated American Billy Papke at the Cirque du Paris on March 5, 1913, in a fifteenth-round disqualification. The referee stopped the fight in the fifteenth as a result of Papke continually ignoring his requests to fight cleanly. Klaus was winning by a significant margin. Papke had been warned throughout the fight for flagrant violations of boxing rules. Klaus received a gold belt for the victory.
In another important win that cemented his claim to the title, Klaus defeated contender Eddie McGoorty on May 24, 1913, in a six-round bout in Pittsburgh. The Pittsburgh Gazette gave Klaus five of the six rounds.
On July 1, 1913, Klaus had an important win where he was awarded a third-round TKO against Jimmy Gardner in Boston. Gardner had contended for the World Welterweight Championship earlier in his career. Gardner put up a great defense until the end of the second round, when Klaus threw some hard punches over the defenses of Gardner. After Klaus continued to connect with hard blows, a second of Gardner's jumped into the ring in the middle of the third round to end the fight. Klaus had faced Gardner on at least three previous occasions.

## Losing the World Middleweight Title to George Chip

During a title fight on 11 October 1913, George Chip baffled the crowd when he knocked out Klaus with a strong right hook to the jaw. The knockout came near the end of the sixth and final round. Prior to the knockout, in the first five rounds, Chip never threatened to take the lead. The fight occurred at the old Pittsburgh City Hall at Market Square . It was the first loss by knockout in Klaus's career. The extra weight Klaus was carrying in his midsection led many reporters to believe he had not trained adequately for the bout, and had underestimated the ability of his opponent.
In a return non-title match on December 23, 1913, Chip defeated Klaus again. In the fifth round of six, the referee stopped the fight resulting in a technical knockout after Chip knocked Klaus to the mat for a second time. In what most considered a decisive win, the Scranton Truth wrote that Chip was the master of Klaus in every way, and clearly deserved the title he had taken from him two months earlier.

## Retirement from boxing and death

Klaus retired from boxing at age 26 shortly after his second loss to George Chip.
Klaus died February 8, 1948, at his home in Pittsburgh, Pennsylvania after a severe heart attack. He was survived by his widow, two sons and three daughters.

## Professional boxing record

All information in this section is derived from BoxRec, unless otherwise stated.

### Official record

| 96 fights | 32 wins | 6 losses |
| By knockout | 21 | 3 |
| By decision | 6 | 2 |
| By disqualification | 5 | 1 |
| Draws | 2 | 2 |
| Newspaper decisions/draws | 56 | 56 |
All newspaper decisions are officially regarded as “no decision” bouts and are not counted in the win/loss/draw column
| No. | Result | Record | Opponent | Type | Round | Date | Location | Notes |
| 96 | Loss | 32–6–2 (56) | George Chip | TKO | 5 (6) | Dec 23, 1913 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 95 | Loss | 32–5–2 (56) | George Chip | TKO | 6 (6) | Oct 11, 1913 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | Lost NYSAC middleweight title |
| 94 | Draw | 32–4–2 (56) | Eddie McGoorty | NWS | 10 | Sep 29, 1913 | Southside A.A., Milwaukee, Wisconsin, U.S. | |
| 93 | Win | 32–4–2 (55) | Jimmy Gardner | TKO | 3 (12) | Jul 1, 1913 | Atlas A.A., Boston, Massachusetts, U.S. | |
| 92 | Loss | 31–4–2 (55) | Jack Dillon | NWS | 10 | May 29, 1913 | Washington Park, Indianapolis, Indiana, U.S. | |
| 91 | Win | 31–4–2 (54) | Eddie McGoorty | NWS | 6 | May 24, 1913 | Exposition Park, Pittsburgh, Pennsylvania, U.S. | |
| 90 | Win | 31–4–2 (53) | Billy Papke | DQ | 15 (20) | Mar 5, 1913 | Cirque de Paris, Paris, Paris, France | Retained NYSAC middleweight title; Claimed world middleweight title |
| 89 | Win | 30–4–2 (53) | Pietro Boine | DQ | 3 (?) | Sep 16, 1912 | Casino-Kursaal, Lyon, Rhône, France | |
| 88 | Win | 29–4–2 (53) | Marcel Moreau | DQ | 4 (15) | Sep 9, 1912 | Villa des Fleurs, Aix-les-Bains, Savoie, France | Moreau was disqualified for hitting low |
| 87 | Win | 28–4–2 (53) | Georges Carpentier | DQ | 19 (20) | Jun 24, 1912 | Grand Hall des Magasins Généraux, Dieppe, Seine-Maritime, France | Retained world middleweight title claim; Won world (title claim) and inaugural NYSAC middleweight titles; Carpentier DQ'd when his manager entered the ring after being hit by two elbows |
| 86 | Win | 27–4–2 (53) | Jack Dillon | NWS | 10 | May 3, 1912 | Madison Square Garden, Manhattan, New York City, New York, U.S. | |
| 85 | Win | 27–4–2 (52) | Jack Dillon | PTS | 20 | Mar 23, 1912 | Coffroth's Arena, Daly City, California, U.S. | Retained world middleweight title claim; Claimed world middleweight title |
| 84 | Win | 26–4–2 (52) | Sailor Ed Petroskey | PTS | 20 | Feb 22, 1912 | Auditorium Pavilion, San Francisco, California, U.S. | Claimed vacant middleweight title |
| 83 | Win | 25–4–2 (52) | George Knockout Brown | NWS | 6 | Jan 29, 1912 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 82 | Win | 25–4–2 (51) | Jimmy Howard | NWS | 6 | Jan 15, 1912 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 81 | Draw | 25–4–2 (50) | Jack Dillon | NWS | 6 | Dec 6, 1911 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 80 | Win | 25–4–2 (49) | Leo Houck | NWS | 6 | Oct 18, 1911 | American A.C., Philadelphia, Pennsylvania, U.S. | |
| 79 | Win | 25–4–2 (48) | Tommy Sullivan | KO | 2 (12) | Oct 12, 1911 | Arena (Armory A.A.), Boston, Massachusetts, U.S. | |
| 78 | Win | 24–4–2 (48) | Cyclone Johnny Thompson | NWS | 10 | Aug 17, 1911 | National A.C., Manhattan, New York City, New York, U.S. | World middleweight title claim at stake; (via KO only) |
| 77 | Win | 24–4–2 (47) | Vic Hansen | KO | 8 (20) | Jul 1, 1911 | Coalinga, California, U.S. | |
| 76 | Win | 23–4–2 (47) | Montana Dan Sullivan | KO | 3 (20) | Jun 15, 1911 | Piedmont Pavilion, Oakland, California, U.S. | |
| 75 | Win | 22–4–2 (47) | Bill MacKinnon | NWS | 6 | May 6, 1911 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 74 | Win | 22–4–2 (46) | Jimmy Gardner | NWS | 6 | Apr 11, 1911 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 73 | Win | 22–4–2 (45) | Montana Jack Sullivan | TKO | 3 (10) | Mar 28, 1911 | Fairmont A.C., Bronx, New York City, New York, U.S. | |
| 72 | Win | 21–4–2 (45) | Leo Houck | PTS | 12 | Feb 14, 1911 | Armory A.A., Boston, Massachusetts, U.S. | |
| 71 | Win | 20–4–2 (45) | Willie Lewis | TKO | 6 (10) | Feb 7, 1911 | Fairmont A.C., Bronx, New York City, New York, U.S. | |
| 70 | Draw | 19–4–2 (45) | Jimmy Gardner | PTS | 12 | Jan 31, 1911 | Armory A.A., Boston, Massachusetts, U.S. | |
| 69 | Win | 19–4–1 (45) | Billy Berger | NWS | 6 | Jan 11, 1911 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 68 | Loss | 19–4–1 (44) | Hugo Kelly | PTS | 12 | Dec 20, 1910 | Armory, Boston, Massachusetts, U.S. | |
| 67 | Win | 19–3–1 (44) | Jack Abbott | TKO | 5 (6) | Dec 15, 1910 | Palisades Rink, McKeesport, Pennsylvania, U.S. | |
| 66 | Loss | 18–3–1 (44) | Jimmy Gardner | PTS | 12 | Nov 29, 1910 | Armory, Boston, Massachusetts, U.S. | |
| 65 | Loss | 18–2–1 (44) | Leo Houck | NWS | 6 | Oct 29, 1910 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 64 | Win | 18–2–1 (43) | Frank Mantell | NWS | 6 | Sep 28, 1910 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 63 | Win | 18–2–1 (42) | Jimmy Gardner | PTS | 12 | Apr 12, 1910 | Armory A.A., Boston, Massachusetts, U.S. | |
| 62 | Win | 17–2–1 (42) | Frank Mantell | KO | 9 (12) | Mar 29, 1910 | Armory A.A., Boston, Massachusetts, U.S. | |
| 61 | Win | 16–2–1 (42) | Stanley Ketchel | NWS | 6 | Mar 23, 1910 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 60 | Win | 16–2–1 (41) | Jack "Twin" Sullivan | PTS | 12 | Jan 18, 1910 | Armory A.A., Boston, Massachusetts, U.S. | |
| 59 | Win | 15–2–1 (41) | Billy Berger | NWS | 6 | Jan 7, 1910 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 58 | Win | 15–2–1 (40) | Porky Dan Flynn | PTS | 12 | Dec 21, 1909 | Armory A.A., Boston, Massachusetts, U.S. | |
| 57 | Loss | 14–2–1 (40) | Joe Thomas | NWS | 6 | Dec 18, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 56 | Draw | 14–2–1 (39) | Harry Lewis | NWS | 6 | Nov 27, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 55 | Win | 14–2–1 (38) | Billy Papke | NWS | 6 | Nov 11, 1909 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 54 | Win | 14–2–1 (37) | Jack Rowan | KO | 2 (6) | Oct 26, 1909 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 53 | Win | 13–2–1 (37) | Hugh McGann | DQ | 3 (6) | Sep 17, 1909 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | McGann took a trouncing before he resorted to fouling |
| 52 | Loss | 12–2–1 (37) | Hugo Kelly | NWS | 6 | Jun 25, 1909 | Bijou Theater, Pittsburgh, Pennsylvania, U.S. | |
| 51 | Win | 12–2–1 (36) | Jack Fitzgerald | NWS | 6 | May 31, 1909 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 50 | Win | 12–2–1 (35) | Harry Mansfield | TKO | 1 (6) | May 15, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 49 | Loss | 11–2–1 (35) | Jim Smith | DQ | 2 (6) | May 15, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 48 | Win | 11–1–1 (35) | Harry Lewis | DQ | 6 (6) | Apr 24, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 47 | Win | 10–1–1 (35) | Harry Mansfield | NWS | 6 | Apr 5, 1909 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 46 | Win | 10–1–1 (34) | Jack Williams | TKO | 2 (6) | Mar 18, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 45 | Win | 9–1–1 (34) | Cy Flynn | TKO | 3 (6) | Mar 4, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 44 | Win | 8–1–1 (34) | Harry Mansfield | NWS | 6 | Feb 18, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 43 | Win | 8–1–1 (33) | Pat Carney | KO | 1 (6) | Feb 11, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 42 | Win | 7–1–1 (33) | Jim Donovan | NWS | 6 | Feb 8, 1909 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 41 | Win | 7–1–1 (32) | Tommy Crawford | TKO | 1 (6) | Jan 15, 1909 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 40 | Win | 6–1–1 (32) | Tommy Lynch | NWS | 6 | Dec 23, 1908 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 39 | Win | 6–1–1 (31) | Paul Moore | NWS | 6 | Dec 22, 1908 | Southside Market House, Pittsburgh, Pennsylvania, U.S. | |
| 38 | Win | 6–1–1 (30) | Billy Clark | KO | 2 (6) | Nov 28, 1908 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 37 | Win | 5–1–1 (30) | Jack Fitzgerald | NWS | 6 | Nov 16, 1908 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 36 | Win | 5–1–1 (29) | Kid Williams | KO | 5 (6) | Oct 30, 1908 | New Amsterdam Opera House, Manhattan, New York City, New York, U.S. | |
| 35 | Win | 4–1–1 (29) | Jim Donovan | NWS | 6 | Oct 24, 1908 | Terminal A.C., Brooklyn, New York City, New York, U.S. | |
| 34 | Win | 4–1–1 (28) | Johnny Carroll | NWS | 6 | Sep 25, 1908 | National S.C., Manhattan, New York City, New York, U.S. | |
| 33 | Loss | 4–1–1 (27) | Jack Robinson | NWS | 6 | Sep 16, 1908 | Mozart Theater, Binghamton, New York, U.S. | |
| 32 | Draw | 4–1–1 (26) | Billy Clark | NWS | 6 | Sep 12, 1908 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 31 | Win | 4–1–1 (25) | Jack Robinson | NWS | 6 | Sep 11, 1908 | National S.C, Manhattan, New York City, New York, U.S. | |
| 30 | Win | 4–1–1 (24) | Dutch Zimmer | KO | 3 (6) | Sep 8, 1908 | Navarre A.C., Manhattan, New York City, New York, U.S. | |
| 29 | Win | 3–1–1 (24) | Jim Donovan | NWS | 6 | Aug 26, 1908 | Navarre A.C., Manhattan, New York City, New York, U.S. | |
| 28 | Win | 3–1–1 (23) | Jack Nelson | NWS | 6 | May 29, 1908 | Roman A.C., Manhattan, New York City, New York, U.S. | |
| 27 | Win | 3–1–1 (22) | Jack Fitzgerald | NWS | 6 | May 7, 1908 | Broadway A.C., Philadelphia, Pennsylvania, U.S. | |
| 26 | Win | 3–1–1 (21) | Cub White | NWS | 6 | May 4, 1908 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 25 | Draw | 3–1–1 (20) | Billy Clark | NWS | 6 | Mar 28, 1908 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 24 | Win | 3–1–1 (19) | Alex Laird | KO | 2 (6) | Mar 16, 1908 | Latrobe, Pennsylvania, U.S. | |
| 23 | Win | 2–1–1 (19) | Paul Moore | NWS | 6 | Dec 10, 1907 | Rankin Athletic Club Rooms, Rankin, Pennsylvania, U.S. | |
| 22 | Loss | 2–1–1 (18) | Dick Given | NWS | 6 | Oct 28, 1907 | Rankin, Pennsylvania, U.S. | |
| 21 | Win | 2–1–1 (17) | Andy Diamond | KO | 1 (6) | Sep 14, 1907 | Donora, Pennsylvania, U.S. | |
| 20 | Win | 1–1–1 (17) | Al Martin | NWS | 6 | May 28, 1907 | Greensburg, Pennsylvania, U.S. | |
| 19 | Loss | 1–1–1 (16) | Paul Moore | NWS | 6 | Jan 10, 1907 | East Pittsburgh, Pennsylvania, U.S. | |
| 18 | Win | 1–1–1 (15) | Jock Simcoe | NWS | 6 | Dec 20, 1906 | McKeesport, Pennsylvania, U.S. | |
| 17 | Draw | 1–1–1 (14) | Paul Moore | NWS | 6 | Dec 11, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 16 | Win | 1–1–1 (13) | James Frazier | NWS | 6 | Nov 12, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 15 | Win | 1–1–1 (12) | Tom Broderick | TKO | 3 (6) | Oct 29, 1906 | Art Club, Ambridge, Pennsylvania, U.S. | |
| 14 | Win | 0–1–1 (12) | George Decker | NWS | 6 | Oct 9, 1906 | Mutual Benefit Hall, East Pittsburgh, Pennsylvania, U.S. | |
| 13 | Draw | 0–1–1 (11) | George Fraser | PTS | 32 (?) | Aug 25, 1906 | Lorain, Ohio, U.S. | This was to be a fight to the finish and was held in secret to avoid police interference; Referee Dime stopped the bout and called it a draw |
| 12 | Draw | 0–1 (11) | Jack Bruce | NWS | 4 | May 8, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 11 | Win | 0–1 (10) | Ned Chernoff | NWS | 4 | Mar 26, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 10 | Draw | 0–1 (9) | Mike Ward | NWS | 4 | Feb 27, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 9 | Win | 0–1 (8) | Dick Given | NWS | 4 | Jan 25, 1906 | Turner Hall, East Pittsburgh, Pennsylvania, U.S. | |
| 8 | Draw | 0–1 (7) | Frank Diamond | NWS | 6 | Jan 24, 1906 | Oakland Armory, Pittsburgh, Pennsylvania, U.S. | |
| 7 | Win | 0–1 (6) | Jock Simcoe | NWS | 6 | Dec 14, 1905 | East Pittsburgh, Pennsylvania, U.S. | |
| 6 | Loss | 0–1 (5) | Elmer Morgan | KO | 4 (6) | Jul 27, 1905 | Mutual Benefit Hall, East Pittsburgh, Pennsylvania, U.S. | |
| 5 | Win | 0–0 (5) | Battling Simpson | NWS | 4 | Mar 27, 1905 | Wilmerding A.C., Wilmerding, Pennsylvania, U.S. | Listed as on Mar 28, but stated that it happened the previous night |
| 4 | Draw | 0–0 (4) | John Ulm | NWS | 4 | Mar 27, 1905 | Wilmerding A.C., Wilmerding, Pennsylvania, U.S. | |
| 3 | Loss | 0–0 (3) | Frank Diamond | NWS | 4 | Mar 4, 1905 | Business Men's Club, Pittsburgh, Pennsylvania, U.S. | |
| 2 | Loss | 0–0 (2) | Frank Diamond | NWS | 4 | Feb 25, 1905 | Business Men's Club, Pittsburgh, Pennsylvania, U.S. | |
| 1 | Draw | 0–0 (1) | Patsy Hogan | NWS | 4 | Feb 18, 1905 | Business Men's Club, Pittsburgh, Pennsylvania, U.S. | |

### Unofficial record

| 96 fights | 68 wins | 15 losses |
| By knockout | 21 | 3 |
| By decision | 42 | 11 |
| By disqualification | 5 | 1 |
| Draws | 13 | 13 |
Record with the inclusion of newspaper decision in the win/loss/draw column.
| No. | Result | Record | Opponent | Type | Round | Date | Location | Notes |
| 96 | Loss | 68–15–13 | George Chip | TKO | 5 (6) | Dec 23, 1913 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 95 | Loss | 68–14–13 | George Chip | TKO | 6 (6) | Oct 11, 1913 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | Lost NYSAC middleweight title |
| 94 | Draw | 68–13–13 | Eddie McGoorty | NWS | 10 | Sep 29, 1913 | Southside A.A., Milwaukee, Wisconsin, U.S. | |
| 93 | Win | 68–13–12 | Jimmy Gardner | TKO | 3 (12) | Jul 1, 1913 | Atlas A.A., Boston, Massachusetts, U.S. | |
| 92 | Loss | 67–13–12 | Jack Dillon | NWS | 10 | May 29, 1913 | Washington Park, Indianapolis, Indiana, U.S. | |
| 91 | Win | 67–12–12 | Eddie McGoorty | NWS | 6 | May 24, 1913 | Exposition Park, Pittsburgh, Pennsylvania, U.S. | |
| 90 | Win | 66–12–12 | Billy Papke | DQ | 15 (20) | Mar 5, 1913 | Cirque de Paris, Paris, Paris, France | Retained NYSAC middleweight title; Claimed world middleweight title |
| 89 | Win | 65–12–12 | Pietro Boine | DQ | 3 (?) | Sep 16, 1912 | Casino-Kursaal, Lyon, Rhône, France | |
| 88 | Win | 64–12–12 | Marcel Moreau | DQ | 4 (15) | Sep 9, 1912 | Villa des Fleurs, Aix-les-Bains, Savoie, France | Moreau was disqualified for hitting low |
| 87 | Win | 63–12–12 | Georges Carpentier | DQ | 19 (20) | Jun 24, 1912 | Grand Hall des Magasins Généraux, Dieppe, Seine-Maritime, France | Retained world middleweight title claim; Won world (title claim) and inaugural NYSAC middleweight titles; Carpentier DQ'd when his manager entered the ring after being hit by two elbows |
| 86 | Win | 62–12–12 | Jack Dillon | NWS | 10 | May 3, 1912 | Madison Square Garden, Manhattan, New York City, New York, U.S. | |
| 85 | Win | 61–12–12 | Jack Dillon | PTS | 20 | Mar 23, 1912 | Coffroth's Arena, Daly City, California, U.S. | Retained world middleweight title claim; Claimed world middleweight title |
| 84 | Win | 60–12–12 | Sailor Ed Petroskey | PTS | 20 | Feb 22, 1912 | Auditorium Pavilion, San Francisco, California, U.S. | Claimed vacant middleweight title |
| 83 | Win | 59–12–12 | George Knockout Brown | NWS | 6 | Jan 29, 1912 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 82 | Win | 58–12–12 | Jimmy Howard | NWS | 6 | Jan 15, 1912 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 81 | Draw | 57–12–12 | Jack Dillon | NWS | 6 | Dec 6, 1911 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 80 | Win | 57–12–11 | Leo Houck | NWS | 6 | Oct 18, 1911 | American A.C., Philadelphia, Pennsylvania, U.S. | |
| 79 | Win | 56–12–11 | Tommy Sullivan | KO | 2 (12) | Oct 12, 1911 | Arena (Armory A.A.), Boston, Massachusetts, U.S. | |
| 78 | Win | 55–12–11 | Cyclone Johnny Thompson | NWS | 10 | Aug 17, 1911 | National A.C., Manhattan, New York City, New York, U.S. | World middleweight title claim at stake; (via KO only) |
| 77 | Win | 54–12–11 | Vic Hansen | KO | 8 (20) | Jul 1, 1911 | Coalinga, California, U.S. | |
| 76 | Win | 53–12–11 | Montana Dan Sullivan | KO | 3 (20) | Jun 15, 1911 | Piedmont Pavilion, Oakland, California, U.S. | |
| 75 | Win | 52–12–11 | Bill MacKinnon | NWS | 6 | May 6, 1911 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 74 | Win | 51–12–11 | Jimmy Gardner | NWS | 6 | Apr 11, 1911 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 73 | Win | 50–12–11 | Montana Jack Sullivan | TKO | 3 (10) | Mar 28, 1911 | Fairmont A.C., Bronx, New York City, New York, U.S. | |
| 72 | Win | 49–12–11 | Leo Houck | PTS | 12 | Feb 14, 1911 | Armory A.A., Boston, Massachusetts, U.S. | |
| 71 | Win | 48–12–11 | Willie Lewis | TKO | 6 (10) | Feb 7, 1911 | Fairmont A.C., Bronx, New York City, New York, U.S. | |
| 70 | Draw | 47–12–11 | Jimmy Gardner | PTS | 12 | Jan 31, 1911 | Armory A.A., Boston, Massachusetts, U.S. | |
| 69 | Win | 47–12–10 | Billy Berger | NWS | 6 | Jan 11, 1911 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 68 | Loss | 46–12–10 | Hugo Kelly | PTS | 12 | Dec 20, 1910 | Armory, Boston, Massachusetts, U.S. | |
| 67 | Win | 46–11–10 | Jack Abbott | TKO | 5 (6) | Dec 15, 1910 | Palisades Rink, McKeesport, Pennsylvania, U.S. | |
| 66 | Loss | 45–11–10 | Jimmy Gardner | PTS | 12 | Nov 29, 1910 | Armory, Boston, Massachusetts, U.S. | |
| 65 | Loss | 45–10–10 | Leo Houck | NWS | 6 | Oct 29, 1910 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 64 | Win | 45–9–10 | Frank Mantell | NWS | 6 | Sep 28, 1910 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 63 | Win | 44–9–10 | Jimmy Gardner | PTS | 12 | Apr 12, 1910 | Armory A.A., Boston, Massachusetts, U.S. | |
| 62 | Win | 43–9–10 | Frank Mantell | KO | 9 (12) | Mar 29, 1910 | Armory A.A., Boston, Massachusetts, U.S. | |
| 61 | Win | 42–9–10 | Stanley Ketchel | NWS | 6 | Mar 23, 1910 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 60 | Win | 41–9–10 | Jack "Twin" Sullivan | PTS | 12 | Jan 18, 1910 | Armory A.A., Boston, Massachusetts, U.S. | |
| 59 | Win | 40–9–10 | Billy Berger | NWS | 6 | Jan 7, 1910 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 58 | Win | 39–9–10 | Porky Dan Flynn | PTS | 12 | Dec 21, 1909 | Armory A.A., Boston, Massachusetts, U.S. | |
| 57 | Loss | 38–9–10 | Joe Thomas | NWS | 6 | Dec 18, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 56 | Draw | 38–8–10 | Harry Lewis | NWS | 6 | Nov 27, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 55 | Win | 38–8–9 | Billy Papke | NWS | 6 | Nov 11, 1909 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 54 | Win | 37–8–9 | Jack Rowan | KO | 2 (6) | Oct 26, 1909 | Old City Hall, Pittsburgh, Pennsylvania, U.S. | |
| 53 | Win | 36–8–9 | Hugh McGann | DQ | 3 (6) | Sep 17, 1909 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | McGann took a trouncing before he resorted to fouling |
| 52 | Loss | 35–8–9 | Hugo Kelly | NWS | 6 | Jun 25, 1909 | Bijou Theater, Pittsburgh, Pennsylvania, U.S. | |
| 51 | Win | 35–7–9 | Jack Fitzgerald | NWS | 6 | May 31, 1909 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 50 | Win | 34–7–9 | Harry Mansfield | TKO | 1 (6) | May 15, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 49 | Loss | 33–7–9 | Jim Smith | DQ | 2 (6) | May 15, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 48 | Win | 33–6–9 | Harry Lewis | DQ | 6 (6) | Apr 24, 1909 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 47 | Win | 32–6–9 | Harry Mansfield | NWS | 6 | Apr 5, 1909 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 46 | Win | 31–6–9 | Jack Williams | TKO | 2 (6) | Mar 18, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 45 | Win | 30–6–9 | Cy Flynn | TKO | 3 (6) | Mar 4, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 44 | Win | 29–6–9 | Harry Mansfield | NWS | 6 | Feb 18, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 43 | Win | 28–6–9 | Pat Carney | KO | 1 (6) | Feb 11, 1909 | Hiland Theater, Pittsburgh, Pennsylvania, U.S. | |
| 42 | Win | 27–6–9 | Jim Donovan | NWS | 6 | Feb 8, 1909 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 41 | Win | 26–6–9 | Tommy Crawford | TKO | 1 (6) | Jan 15, 1909 | Duquesne Gardens, Pittsburgh, Pennsylvania, U.S. | |
| 40 | Win | 25–6–9 | Tommy Lynch | NWS | 6 | Dec 23, 1908 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 39 | Win | 24–6–9 | Paul Moore | NWS | 6 | Dec 22, 1908 | Southside Market House, Pittsburgh, Pennsylvania, U.S. | |
| 38 | Win | 23–6–9 | Billy Clark | KO | 2 (6) | Nov 28, 1908 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 37 | Win | 22–6–9 | Jack Fitzgerald | NWS | 6 | Nov 16, 1908 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 36 | Win | 21–6–9 | Kid Williams | KO | 5 (6) | Oct 30, 1908 | New Amsterdam Opera House, Manhattan, New York City, New York, U.S. | |
| 35 | Win | 20–6–9 | Jim Donovan | NWS | 6 | Oct 24, 1908 | Terminal A.C., Brooklyn, New York City, New York, U.S. | |
| 34 | Win | 19–6–9 | Johnny Carroll | NWS | 6 | Sep 25, 1908 | National S.C., Manhattan, New York City, New York, U.S. | |
| 33 | Loss | 18–6–9 | Jack Robinson | NWS | 6 | Sep 16, 1908 | Mozart Theater, Binghamton, New York, U.S. | |
| 32 | Draw | 18–5–9 | Billy Clark | NWS | 6 | Sep 12, 1908 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 31 | Win | 18–5–8 | Jack Robinson | NWS | 6 | Sep 11, 1908 | National S.C, Manhattan, New York City, New York, U.S. | |
| 30 | Win | 17–5–8 | Dutch Zimmer | KO | 3 (6) | Sep 8, 1908 | Navarre A.C., Manhattan, New York City, New York, U.S. | |
| 29 | Win | 16–5–8 | Jim Donovan | NWS | 6 | Aug 26, 1908 | Navarre A.C., Manhattan, New York City, New York, U.S. | |
| 28 | Win | 15–5–8 | Jack Nelson | NWS | 6 | May 29, 1908 | Roman A.C., Manhattan, New York City, New York, U.S. | |
| 27 | Win | 14–5–8 | Jack Fitzgerald | NWS | 6 | May 7, 1908 | Broadway A.C., Philadelphia, Pennsylvania, U.S. | |
| 26 | Win | 13–5–8 | Cub White | NWS | 6 | May 4, 1908 | West End A.C., Philadelphia, Pennsylvania, U.S. | |
| 25 | Draw | 12–5–8 | Billy Clark | NWS | 6 | Mar 28, 1908 | National A.C., Philadelphia, Pennsylvania, U.S. | |
| 24 | Win | 12–5–7 | Alex Laird | KO | 2 (6) | Mar 16, 1908 | Latrobe, Pennsylvania, U.S. | |
| 23 | Win | 11–5–7 | Paul Moore | NWS | 6 | Dec 10, 1907 | Rankin Athletic Club Rooms, Rankin, Pennsylvania, U.S. | |
| 22 | Loss | 10–5–7 | Dick Given | NWS | 6 | Oct 28, 1907 | Rankin, Pennsylvania, U.S. | |
| 21 | Win | 10–4–7 | Andy Diamond | KO | 1 (6) | Sep 14, 1907 | Donora, Pennsylvania, U.S. | |
| 20 | Win | 9–4–7 | Al Martin | NWS | 6 | May 28, 1907 | Greensburg, Pennsylvania, U.S. | |
| 19 | Loss | 8–4–7 | Paul Moore | NWS | 6 | Jan 10, 1907 | East Pittsburgh, Pennsylvania, U.S. | |
| 18 | Win | 8–3–7 | Jock Simcoe | NWS | 6 | Dec 20, 1906 | McKeesport, Pennsylvania, U.S. | |
| 17 | Draw | 7–3–7 | Paul Moore | NWS | 6 | Dec 11, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 16 | Win | 7–3–6 | James Frazier | NWS | 6 | Nov 12, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 15 | Win | 6–3–6 | Tom Broderick | TKO | 3 (6) | Oct 29, 1906 | Art Club, Ambridge, Pennsylvania, U.S. | |
| 14 | Win | 5–3–6 | George Decker | NWS | 6 | Oct 9, 1906 | Mutual Benefit Hall, East Pittsburgh, Pennsylvania, U.S. | |
| 13 | Draw | 4–3–6 | George Fraser | PTS | 32 (?) | Aug 25, 1906 | Lorain, Ohio, U.S. | This was to be a fight to the finish and was held in secret to avoid police interference; Referee Dime stopped the bout and called it a draw |
| 12 | Draw | 4–3–5 | Jack Bruce | NWS | 4 | May 8, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 11 | Win | 4–3–4 | Ned Chernoff | NWS | 4 | Mar 26, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 10 | Draw | 3–3–4 | Mike Ward | NWS | 4 | Feb 27, 1906 | Turner Hall, Pittsburgh, Pennsylvania, U.S. | |
| 9 | Win | 3–3–3 | Dick Given | NWS | 4 | Jan 25, 1906 | Turner Hall, East Pittsburgh, Pennsylvania, U.S. | |
| 8 | Draw | 2–3–3 | Frank Diamond | NWS | 6 | Jan 24, 1906 | Oakland Armory, Pittsburgh, Pennsylvania, U.S. | |
| 7 | Win | 2–3–2 | Jock Simcoe | NWS | 6 | Dec 14, 1905 | East Pittsburgh, Pennsylvania, U.S. | |
| 6 | Loss | 1–3–2 | Elmer Morgan | KO | 4 (6) | Jul 27, 1905 | Mutual Benefit Hall, East Pittsburgh, Pennsylvania, U.S. | |
| 5 | Win | 1–2–2 | Battling Simpson | NWS | 4 | Mar 27, 1905 | Wilmerding A.C., Wilmerding, Pennsylvania, U.S. | Listed as on Mar 28, but stated that it happened the previous night |
| 4 | Draw | 0–2–2 | John Ulm | NWS | 4 | Mar 27, 1905 | Wilmerding A.C., Wilmerding, Pennsylvania, U.S. | |
| 3 | Loss | 0–2–1 | Frank Diamond | NWS | 4 | Mar 4, 1905 | Business Men's Club, Pittsburgh, Pennsylvania, U.S. | |
| 2 | Loss | 0–1–1 | Frank Diamond | NWS | 4 | Feb 25, 1905 | Business Men's Club, Pittsburgh, Pennsylvania, U.S. | |
| 1 | Draw | 0–0–1 | Patsy Hogan | NWS | 4 | Feb 18, 1905 | Business Men's Club, Pittsburgh, Pennsylvania, U.S. | |

## Boxing achievements

Titles in pretence :
| Vacant | World Middleweight Champion February 22, 1912 – March 5, 1913 won undisputed title | VacantTitle next held byEddie McGoorty Australian recognition |
| Achievements |||
| Preceded byStanley Ketchel Died | World Middleweight Champion 5 March 1913 – 11 October 1913 | Succeeded byGeorge Chip |

## Honors

Klaus was elected into the International Boxing Hall of Fame in 2008.