| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. G Mazzoni vs M Johansson |
| 1-0 | 51 | 1964 | Tel Aviv Olympiad qual-3 | B49 Sicilian, Taimanov Variation |
| 27. G Mazzoni vs E O'Hare |
| 1-0 | 28 | 1964 | Tel Aviv Olympiad qual-3 | B76 Sicilian, Dragon, Yugoslav Attack |
| 28. R Schneider vs G Mazzoni |
| 0-1 | 38 | 1964 | Tel Aviv Olympiad qual-3 | B90 Sicilian, Najdorf |
| 29. G Mazzoni vs Y Kraidman |
| ½-½ | 36 | 1964 | Tel Aviv Olympiad qual-3 | C97 Ruy Lopez, Closed, Chigorin |
| 30. J M Aitken vs G Mazzoni |
| ½-½ | 64 | 1964 | Tel Aviv Olympiad qual-3 | B93 Sicilian, Najdorf, 6.f4 |
| 31. G Mazzoni vs B Thorsteinsson |
| 0-1 | 72 | 1964 | Tel Aviv Olympiad Final-C | C84 Ruy Lopez, Closed |
| 32. E Bhend vs G Mazzoni |
| ½-½ | 32 | 1964 | Tel Aviv Olympiad Final-C | C84 Ruy Lopez, Closed |
| 33. G Mazzoni vs G Villarroel |
 | 1-0 | 30 | 1964 | Tel Aviv Olympiad Final-C | C84 Ruy Lopez, Closed |
| 34. Westerinen vs G Mazzoni |
| 1-0 | 26 | 1964 | Tel Aviv Olympiad Final-C | D15 Queen's Gambit Declined Slav |
| 35. G Mazzoni vs Y Safvat |
| 0-1 | 40 | 1964 | Tel Aviv Olympiad Final-C | C99 Ruy Lopez, Closed, Chigorin, 12...cd |
| 36. G Mazzoni vs J Minaya |
| 1-0 | 30 | 1964 | Tel Aviv Olympiad Final-C | B68 Sicilian, Richter-Rauzer Attack, 7...a6 Defense, 9...Be7 |
| 37. A Paidousis vs G Mazzoni |
| ½-½ | 41 | 1964 | Tel Aviv Olympiad Final-C | A46 Queen's Pawn Game |
| 38. G Mazzoni vs J M Boey |
| 0-1 | 17 | 1966 | Havana Olympiad Final-B | C63 Ruy Lopez, Schliemann Defense |
| 39. G Mazzoni vs Bobotsov |
| 1-0 | 80 | 1966 | Le Havre | B97 Sicilian, Najdorf |
| 40. G Mazzoni vs Larsen |
| 0-1 | 54 | 1966 | Le Havre | B61 Sicilian, Richter-Rauzer, Larsen Variation, 7.Qd2 |
| 41. N Krogius vs G Mazzoni |
| 1-0 | 42 | 1966 | Le Havre | E69 King's Indian, Fianchetto, Classical Main line |
| 42. C Boutteville vs G Mazzoni |
| ½-½ | 35 | 1966 | Le Havre | A07 King's Indian Attack |
| 43. A Matanovic vs G Mazzoni |
| 1-0 | 83 | 1966 | Le Havre | C96 Ruy Lopez, Closed |
| 44. G Mazzoni vs A Dueckstein |
| 0-1 | 27 | 1966 | Le Havre | C18 French, Winawer |
| 45. G Mazzoni vs Forintos |
| ½-½ | 14 | 1966 | Le Havre | B43 Sicilian, Kan, 5.Nc3 |
| 46. G Mazzoni vs P Rolland |
| 1-0 | 29 | 1966 | Le Havre | C84 Ruy Lopez, Closed |
| 47. G Mazzoni vs S Zinser |
| 1-0 | 33 | 1966 | Le Havre | C92 Ruy Lopez, Closed |
| 48. Polugaevsky vs G Mazzoni |
| 1-0 | 33 | 1966 | Le Havre | E11 Bogo-Indian Defense |
| 49. M Roos vs G Mazzoni |
| ½-½ | 17 | 1966 | Le Havre | A13 English |
| 50. G Mazzoni vs Kavalek |
| 0-1 | 42 | 1966 | The Hague Zonal | B81 Sicilian, Scheveningen, Keres Attack |
Kibitzing
