| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. DeFirmian vs V Raicevic |
| ½-½ | 42 |
1980 |
Lone Pine | C00 French Defense |
| 2. DeFirmian vs M Despotovic |
| 0-1 | 35 |
1981 |
Smederevska Palanka (Yugoslavia) | C05 French, Tarrasch |
| 3. DeFirmian vs S Bjarnason |
| 1-0 | 34 |
1982 |
Reykjavik (Iceland) | C18 French, Winawer |
| 4. DeFirmian vs M Bjelajac |
| 1-0 | 50 |
1983 |
It (cat.10) | C10 French |
| 5. DeFirmian vs D Glueck |
| 1-0 | 50 |
1983 |
Pasadena (USA) | C19 French, Winawer, Advance |
| 6. DeFirmian vs B Kogan |
| 1-0 | 38 |
1983 |
Ch USA | C16 French, Winawer |
| 7. DeFirmian vs R Henley |
| ½-½ | 57 |
1984 |
Ch USA | C19 French, Winawer, Advance |
| 8. DeFirmian vs J L Watson |
| 0-1 | 27 |
1984 |
Ch USA | C19 French, Winawer, Advance |
| 9. DeFirmian vs A Chernin |
 | 1-0 | 43 |
1985 |
Izt | C19 French, Winawer, Advance |
| 10. DeFirmian vs A Chernin |
| 1-0 | 58 |
1986 |
Wijk aan Zee (Netherlands) | C11 French |
| 11. DeFirmian vs Fedorowicz |
| ½-½ | 15 |
1986 |
USA-ch | C15 French, Winawer |
| 12. DeFirmian vs G Garcia |
| ½-½ | 40 |
1986 |
Olympiad | C19 French, Winawer, Advance |
| 13. DeFirmian vs Christiansen |
| ½-½ | 20 |
1987 |
Ch USA | C10 French |
| 14. DeFirmian vs Rohde |
| 0-1 | 93 |
1987 |
Ch USA | C16 French, Winawer |
| 15. DeFirmian vs G Rey |
| 1-0 | 45 |
1987 |
Ch USA | C19 French, Winawer, Advance |
| 16. DeFirmian vs A Chernin |
| ½-½ | 30 |
1988 |
It (open) | C14 French, Classical |
| 17. DeFirmian vs D Edelman |
| 1-0 | 32 |
1988 |
It (open) | C19 French, Winawer, Advance |
| 18. DeFirmian vs G Garcia Gonzales |
| 0-1 | 30 |
1988 |
It (open) | C19 French, Winawer, Advance |
| 19. DeFirmian vs R Reyes |
| 1-0 | 38 |
1988 |
It (open) | C19 French, Winawer, Advance |
| 20. DeFirmian vs S Jacobi |
| 1-0 | 41 |
1989 |
New York (USA) | C10 French |
| 21. DeFirmian vs Ulf Andersson |
| ½-½ | 32 |
1989 |
Reggio Emilia8990 | C11 French |
| 22. DeFirmian vs I Rogers |
| 1-0 | 75 |
1989 |
Cup World (open) | C19 French, Winawer, Advance |
| 23. DeFirmian vs Hebert |
| 1-0 | 23 |
1989 |
San Mateo (USA) | C19 French, Winawer, Advance |
| 24. DeFirmian vs Seirawan |
| ½-½ | 15 |
1989 |
Ch USA | C14 French, Classical |
| 25. DeFirmian vs Dreev |
| 0-1 | 35 |
1989 |
It (open) | C14 French, Classical |
