| 2003-07-11 | Davis Cup G1 PO: VEN vs CHI | Hard | RR | 475 |  Kepler Orellana | 44 |  Marcelo Rios | 7-6(4) RET | H2H | 5 | - | - | - | - | - | - | - |
| 2003-07-11 | Davis Cup G1 PO: VEN vs CHI | Hard | RR | 324 | Jose De Armas | 44 | Marcelo Rios | 7-5 6-2 3-6 3-6 8-6 | H2H | 5 | - | - | - | - | - | - | - |
| 2003-05-26 | Roland Garros | Clay | R128 | 74 |  Mario Ancic | 42 | Marcelo Rios | 6-1 1-0 RET | H2H | 5 | 36 | 1 | 0 | 34.8% | 87.5% | 73.3% | 2/2 |
| 2003-05-19 | World Team Championship | Clay | F | 47 |  Radek Stepanek | 42 | Marcelo Rios | 6-3 7-6(5) | H2H | 3 | 64 | 3 | 1 | 63.5% | 75.8% | 57.9% | 1/2 |
| 2003-05-19 | World Team Championship | Clay | RR | 102 |  Tomas Behrend | 42 | Marcelo Rios | 3-6 7-5 7-6(2) | H2H | 3 | 64 | 3 | 1 | 63.5% | 75.8% | 57.9% | 1/2 |
| 2003-05-19 | World Team Championship | Clay | RR | 42 | Marcelo Rios | 22 |  Gaston Gaudio | 6-3 6-3 | H2H | 3 | 64 | 3 | 1 | 63.5% | 75.8% | 57.9% | 1/2 |
| 2003-03-17 | Miami Masters | Hard | R32 | 31 | Marcelo Rios (28) | 3 |  Juan Carlos Ferrero (3) | 6-3 7-6(2) | H2H | 3 | 98 | 6 | 4 | 68.1% | 74.5% | 54.5% | 2/3 |
| 2003-03-17 | Miami Masters | Hard | R64 | 31 | Marcelo Rios (28) | 41 |  Taylor Dent | 6-1 6-1 | H2H | 3 | 59 | 3 | 0 | 68.1% | 75.0% | 53.3% | 2/2 |
| 2003-03-10 | Indian Wells Masters | Hard | R32 | 36 |  Max Mirnyi | 29 | Marcelo Rios | 6-3 6-3 | H2H | 3 | 62 | 9 | 2 | 54.9% | 85.7% | 56.5% | 0/0 |
| 2003-03-10 | Indian Wells Masters | Hard | R64 | 29 | Marcelo Rios | 20 | Gaston Gaudio (17) | 4-0 RET | H2H | 3 | 14 | 1 | 0 | 50.0% | 100.0% | 100.0% | 0/0 |
