| 11‑Aug‑2003 | Cincinnati Masters | Hard | R64 | 24 | 33 | Arnaud Clement [FRA] d. Costa | 7-6(5) 6-4 | | 0.89 | 2.6% | 3.9% | 66.2% | 68.6% | 50.0% | 6/9 | 1:58 |
| 5‑Aug‑2002 | Cincinnati Masters | Hard | R32 | 7 | 44 | Wayne Ferreira [RSA] d. (7)Costa | 7-6(6) 6-2 | | 0.84 | 5.4% | 2.7% | 56.8% | 61.9% | 37.5% | 2/6 | 1:33 |
| 5‑Aug‑2002 | Cincinnati Masters | Hard | R64 | 7 | 27 | (7)Costa d. Nicolas Lapentti [ECU] | 4-6 7-6(4) 6-4 | | 0.75 | 11.2% | 0.9% | 58.9% | 76.2% | 59.1% | 5/6 | 2:45 |
| 6‑Aug‑2001 | Cincinnati Masters | Hard | R64 | 41 | 47 | Max Mirnyi [BLR] d. Costa | 6-3 6-4 | | 0.84 | 2.1% | 0.0% | 57.4% | 66.7% | 50.0% | 1/4 | 1:10 |
| 7‑Aug‑2000 | Cincinnati Masters | Hard | R64 | 25 | 107 | (LL)Andrea Gaudenzi [ITA] d. Costa | 6-3 3-6 6-1 | | 0.77 | 7.0% | 5.8% | 53.5% | 69.6% | 42.5% | 7/11 | 1:55 |
| 9‑Aug‑1999 | Cincinnati Masters | Hard | R32 | 22 | 42 | Jiri Novak [CZE] d. (14)Costa | 7-6(3) 7-6(6) | | 0.84 | 4.8% | 1.2% | 63.1% | 67.9% | 51.6% | 6/8 | 1:35 |
| 9‑Aug‑1999 | Cincinnati Masters | Hard | R64 | 22 | 52 | (14)Costa d. Andrew Ilie [AUS] | 6-4 3-6 6-2 | | 1.12 | 4.7% | 1.2% | 68.6% | 69.5% | 55.6% | 10/11 | 1:49 |
| 10‑Aug‑1998 | Cincinnati Masters | Hard | R32 | 14 | 40 | Tommy Haas [GER] d. (12)Costa | 6-1 6-3 | | 0.50 | 3.3% | 1.6% | 80.3% | 53.1% | 33.3% | 7/11 | 1:02 |
| 10‑Aug‑1998 | Cincinnati Masters | Hard | R64 | 14 | 97 | (12)Costa d. (Q)Sebastien Grosjean [FRA] | 1-6 6-4 6-1 | | 1.09 | 5.4% | 2.7% | 66.2% | 67.3% | 48.0% | 7/10 | 1:30 |
| 4‑Aug‑1997 | Cincinnati Masters | Hard | SF | 17 | 1 | (1)Pete Sampras [USA] d. (14)Costa | 6-3 6-4 | (ch) | 0.52 | 11.5% | 3.3% | 68.9% | 73.8% | 21.1% | 5/8 | 1:04 |
| 4‑Aug‑1997 | Cincinnati Masters | Hard | QF | 17 | 8 | (14)Costa d. (6)Sergi Bruguera [ESP] | 4-6 6-3 5-2 RET | | 1.20 | 11.3% | 1.3% | 75.0% | 66.7% | 55.0% | 7/10 | 1:56 |
| 4‑Aug‑1997 | Cincinnati Masters | Hard | R16 | 17 | 5 | (14)Costa d. (4)Alex Corretja [ESP] | 6-1 7-6(3) | | 1.54 | 5.1% | 6.8% | 57.6% | 88.2% | 52.0% | 1/2 | 1:28 |
| 4‑Aug‑1997 | Cincinnati Masters | Hard | R32 | 17 | 72 | (14)Costa d. Tommy Haas [GER] | 6-3 6-4 | | 2.26 | 4.1% | 0.0% | 71.4% | 88.6% | 64.3% | 0/0 | 1:02 |
| 4‑Aug‑1997 | Cincinnati Masters | Hard | R64 | 17 | 22 | (14)Costa d. Jim Courier [USA] | 4-6 7-6(5) 6-3 | | 1.18 | 5.0% | 0.0% | 67.3% | 75.0% | 60.6% | 4/5 | 2:24 |