Croatia: Umag - Singles - Main |
| Quarter-finals | Oresar B. | Sanchez J. | 0:2 (2:6, 62:7) | details | 17.05.1991 |
| 1/8-finals | Oncins J. | Oresar B. | 1:2 (4:6, 6:4, 3:6) | details | 15.05.1991 |
| 1/16-finals | Merinov A. | Oresar B. | 0:2 (2:6, 2:6) | details | 13.05.1991 |
USA: Tampa - Singles - Main |
| 1/8-finals | Reneberg R. | Oresar B. | 2:0 (6:3, 6:4) | details | 01.05.1991 |
| 1/16-finals | Wuyts B. | Oresar B. | 0:2 (3:6, 1:6) | details | 29.04.1991 |
Australia: Australian Open - Singles - Qualification |
| Semi-finals | Oresar B. | Patten D. | 0:2 (2:6, 4:6) | details | 16.01.1991 |
Brazil: Sao Paulo 2 - Singles - Main |
| 1/8-finals | Oresar B. | Mattar L. | 1:2 (5:7, 6:2, 4:6) | details | 24.10.1990 |
| 1/16-finals | Oresar B. | Pescosolido S. | 2:0 (6:4, 6:2) | details | 22.10.1990 |
Switzerland: Geneva - Singles - Main |
| 1/16-finals | Camporese O. | Oresar B. | 2:0 (6:4, 6:4) | details | 10.09.1990 |
Austria: Kitzbuhel - Singles - Main |
| 1/32-finals | Oresar B. | Lopez-Montoya G. | 0:2 (6:7, 3:6) | details | 30.07.1990 |
Sweden: Bastad - Singles - Main |
| 1/16-finals | Filippini M. | Oresar B. | 2:0 (6:3, 6:2) | details | 09.07.1990 |
United Kingdom: Wimbledon - Singles - Main |
| 1/64-finals | Gilbert B. | Oresar B. | 3:2 (6:1, 3:6, 4:6, 6:1, 6:2) | details | 30.06.1990 |
Italy: Genoa - Singles - Main |
| 1/16-finals | Oresar B. | Clavet F. | 0:2 (3:6, 3:6) | details | 18.06.1990 |
Italy: Florence - Singles - Main |
| 1/16-finals | Clavet F. | Oresar B. | 2:0 (6:1, 7:6) | details | 11.06.1990 |
France: French Open - Singles - Main |
| 1/32-finals | Oresar B. | Leconte H. | 0:3 (4:6, 2:6, 1:6) | details | 31.05.1990 |
| 1/64-finals | Jelen E. | Oresar B. | 2:3 (6:7, 6:4, 6:2, 1:6, 4:6) | details | 28.05.1990 |
Germany: Munich - Singles - Main |
| 1/8-finals | Oresar B. | Courier J. | 0:2 (2:6, 1:6) | details | 01.05.1990 |
| 1/16-finals | Oresar B. | Stich M. | 2:1 (7:6, 6:7, 6:4) | details | 30.04.1990 |
Spain: Barcelona - Singles - Main |
| 1/32-finals | Oresar B. | Schapers M. | 1:2 (2:6, 6:4, 5:7) | details | 09.04.1990 |
USA: Miami - Singles - Main |
| 1/32-finals | Oresar B. | Gomez A. | 1:2 (6:2, 2:6, 3:6) | details | 18.03.1990 |
| 1/64-finals | Cash P. | Oresar B. | 0:2 (2:6, 2:6) | details | 16.03.1990 |
USA: Memphis - Singles - Main |
| 1/16-finals | Oresar B. | Chamberlin P. | 0:2 (5:7, 4:6) | details | 28.02.1990 |
| 1/32-finals | Jones K. | Oresar B. | 0:2 (6:7, 3:6) | details | 26.02.1990 |
Canada: Toronto 2 - Singles - Main |
| 1/16-finals | Srejber M. | Oresar B. | 2:1 (4:6, 6:4, 6:2) | details | 13.02.1990 |
| 1/32-finals | Oresar B. | Van Emburgh G. | 2:1 (6:4, 6:7, 6:2) | details | 12.02.1990 |
Italy: Milan - Singles - Main |
| 1/16-finals | Oresar B. | Cane P. | 0:2 (6:7, 4:6) | details | 05.02.1990 |
Australia: Australian Open - Singles - Main |
| 1/32-finals | Gomez A. | Oresar B. | 3:1 (6:4, 3:6, 6:3, 6:2) | details | 18.01.1990 |
| 1/64-finals | Witsken T. | Oresar B. | 0:3 (4:6, 1:6, 4:6) | details | 15.01.1990 |
Australia: Adelaide - Singles - Main |
| 1/16-finals | Oresar B. | Annacone P. | 0:2 (1:6, 4:6) | details | 01.01.1990 |