| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. B Rogulj vs DeFirmian |
| 1-0 | 42 |
1976 |
USA | B92 Sicilian, Najdorf, Opocensky Variation |
| 2. G Sigurjonsson vs DeFirmian |
| ½-½ | 31 |
1979 |
Lone Pine (USA) | B92 Sicilian, Najdorf, Opocensky Variation |
| 3. G Ligterink vs DeFirmian |
| ½-½ | 44 |
1979 |
Lone Pine (USA) | B92 Sicilian, Najdorf, Opocensky Variation |
| 4. Unzicker vs DeFirmian |
| 1-0 | 41 |
1981 |
It (cat.9) | B92 Sicilian, Najdorf, Opocensky Variation |
| 5. B Abramovic vs DeFirmian |
| 1-0 | 56 |
1982 |
Reykjavik (Iceland) | B92 Sicilian, Najdorf, Opocensky Variation |
| 6. I Morovic vs DeFirmian |
 | ½-½ | 19 |
1985 |
Izt | B92 Sicilian, Najdorf, Opocensky Variation |
| 7. Hjartarson vs DeFirmian |
| 1-0 | 32 |
1986 |
It (open) | B92 Sicilian, Najdorf, Opocensky Variation |
| 8. B Abramovic vs DeFirmian |
| 0-1 | 39 |
1986 |
It (cat.7) | B92 Sicilian, Najdorf, Opocensky Variation |
| 9. Barbulescu vs DeFirmian |
| ½-½ | 24 |
1986 |
Olympiad | B92 Sicilian, Najdorf, Opocensky Variation |
| 10. Rohde vs DeFirmian |
| 1-0 | 53 |
1986 |
USA-ch | B92 Sicilian, Najdorf, Opocensky Variation |
| 11. E De Castro vs DeFirmian |
| 0-1 | 57 |
1986 |
Olympiad | B92 Sicilian, Najdorf, Opocensky Variation |
| 12. Marjanovic vs DeFirmian |
| 0-1 | 59 |
1987 |
Kolhapur (India) | B92 Sicilian, Najdorf, Opocensky Variation |
| 13. P Thipsay vs DeFirmian |
| 1-0 | 49 |
1987 |
Kolhapur (India) | B92 Sicilian, Najdorf, Opocensky Variation |
| 14. P Haba vs DeFirmian |
| ½-½ | 48 |
1988 |
Olympiad | B92 Sicilian, Najdorf, Opocensky Variation |
| 15. Huzman vs DeFirmian |
 | 0-1 | 51 |
1989 |
Cup World (open) | B92 Sicilian, Najdorf, Opocensky Variation |
| 16. L Aubert vs DeFirmian |
| 1-0 | 67 |
1989 |
New York (USA) | B92 Sicilian, Najdorf, Opocensky Variation |
| 17. Wahls vs DeFirmian |
| ½-½ | 39 |
1990 |
Biel | B92 Sicilian, Najdorf, Opocensky Variation |
| 18. M Brooks vs DeFirmian |
| 0-1 | 56 |
1990 |
It (open) | B92 Sicilian, Najdorf, Opocensky Variation |
| 19. Sherzer vs DeFirmian |
| ½-½ | 56 |
1990 |
Ch USA | B92 Sicilian, Najdorf, Opocensky Variation |
| 20. G Astrom vs DeFirmian |
| 0-1 | 36 |
1994 |
Cup Rilton | B92 Sicilian, Najdorf, Opocensky Variation |
| 21. J Klovans vs DeFirmian |
| ½-½ | 48 |
1994 |
It (open) | B92 Sicilian, Najdorf, Opocensky Variation |
| 22. Kasparov vs DeFirmian |
| 1-0 | 54 |
1995 |
Intel Chess Grand Prix (active) | B92 Sicilian, Najdorf, Opocensky Variation |
| 23. M Brooks vs DeFirmian |
| ½-½ | 52 |
1995 |
Chicago (USA) | B92 Sicilian, Najdorf, Opocensky Variation |
| 24. E Lindschau vs DeFirmian |
| 0-1 | 30 |
1997 |
Wichern op 4th | B92 Sicilian, Najdorf, Opocensky Variation |
| 25. A Zatonskih vs DeFirmian |
| ½-½ | 45 |
2004 |
Chessmaster US Championships 2005 | B92 Sicilian, Najdorf, Opocensky Variation |