# 1999 Sybase Open – Singles

Andre Agassi was the defending champion, but was defaulted in his second round match against Cecil Mamiit for swearing at a line judge.
Mark Philippoussis won the title, defeating Mamiit 6–3, 6–2 in the final.

## Seeds

* Pete Sampras (semifinals, withdrew because of an ankle injury)
* Andre Agassi (second round, defaulted)
* Mark Philippoussis (champion)
* Michael Chang (semifinals)
* Mariano Puerta (first round)
* Jan-Michael Gambill (first round)
* Mariano Zabaleta (first round)
* Ramón Delgado (second round)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| 1 | Pete Sampras | | | | | | | |
| 3 | Mark Philippoussis | w/o | | | | | | |
| 3 | Mark Philippoussis | w/o | | | 3 | Mark Philippoussis | 6 | 6 |
| | | | | | Q | Cecil Mamiit | 3 | 2 |
| 4 | Michael Chang | 6 | 3 | 4 | Q | Cecil Mamiit | 3 | 2 |
| Q | Cecil Mamiit | 3 | 6 | 6 | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals |
| 1 | P Sampras | 6 | 6 | | | | | | | | | | | | | | |
| | G Blanco | 4 | 4 | | 1 | P Sampras | 7 | 6 | | | | | | | | | |
| | M Rodríguez | 6 | 6$^2$ | 6 | | M Rodríguez | 5 | 3 | | | | | | | | | |
| Q | A Hernández | 4 | 7$^7$ | 3 | | | | | | 1 | P Sampras | 7 | 6 | | | | |
| Q | B Karbacher | 6 | 6 | | | | | | | Q | B Karbacher | 5 | 3 | | | | |
| | S Koubek | 3 | 2 | | Q | B Karbacher | 6 | 6$^5$ | 6 | | | | | | | | |
| | S Lareau | 6 | 6 | | | S Lareau | 3 | 7$^7$ | 3 | | | | | | | | |
| 7 | M Zabeleta | 2 | 1 | | | | | | | | | | | | 1 | P Sampras | |
| 3 | M Philippoussis | 6$^2$ | 7 | 6 | | | | | | | | | | | 3 | M Philippoussis | w/o |
| | S Sargsian | 7$^7$ | 5 | 3 | 3 | M Philippoussis | 6 | 6 | | | | | | | | | |
| | J Courier | 4 | 6$^4$ | | | J van Lottum | 2 | 1 | | | | | | | | | |
| | J van Lottum | 6 | 7$^7$ | | | | | | | 3 | M Philippoussis | 6 | 3 | 7$^7$ | | | |
| Q | R Agénor | 6 | 2 | 3 | | | | | | WC | J Gimelstob | 2 | 6 | 6$^0$ | | | |
| WC | C Woodruff | 2 | 6 | 6 | WC | C Woodruff | 4 | 6$^3$ | | | | | | | | | |
| WC | J Gimelstob | 6 | 7$^8$ | | WC | J Gimelstob | 6 | 7$^7$ | | | | | | | | | |
| 6 | J-M Gambill | 3 | 6$^6$ | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | M Puerta | 2 | 6 | 3 | | | | | | | | | | | | | | |
| | C Ruud | 6 | 4 | 6 | | C Ruud | 6 | 7$^7$ | | | | | | | | | | |
| | C Costa | 6 | 4 | 4 | WC | P Goldstein | 1 | 6$^4$ | | | | | | | | | | |
| WC | P Goldstein | 4 | 6 | 6 | | | | | | C Ruud | 1 | 5 | | | | | | |
| | F Squillari | 6 | 3 | 6 | | | | | 4 | M Chang | 6 | 7 | | | | | | |
| | A Portas | 1 | 6 | 2 | | F Squillari | 4 | 6$^5$ | | | | | | | | | | |
| | F Meligeni | 3 | 2 | | 4 | M Chang | 6 | 7$^7$ | | | | | | | | | | |
| 4 | M Chang | 6 | 6 | | | | | | | | | | | 4 | M Chang | 6 | 3 | 4 |
| 8 | R Delgado | 5 | 6 | 7 | | | | | | | | | | Q | C Mamiit | 3 | 6 | 6 |
| | B Steven | 7 | 4 | 5 | 8 | R Delgado | 2 | 3 | | | | | | | | | | |
| | S Campbell | 3 | 6 | 5 | | M Woodforde | 6 | 6 | | | | | | | | | | |
| | M Woodforde | 6 | 3 | 7 | | | | | | M Woodforde | 6$^5$ | 6 | 3 | | | | | |
| Q | C Mamiit | 2 | 6 | 7 | | | | | Q | C Mamiit | 7$^7$ | 4 | 6 | | | | | |
| | K Carlsen | 6 | 3 | 5 | Q | C Mamiit | 0 | 6 | | | | | | | | | | |
| | T Woodbridge | 2 | 1 | | 2 | A Agassi | 6 | 6$^d$ | | | | | | | | | | |
| 2 | A Agassi | 6 | 6 | | | | | | | | | | | | | | | |