| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. E Marchand vs P Lapiken |
| 1-0 | 78 | 1956 | 57th US Open | E92 King's Indian |
| 27. P Lapiken vs B Rozsa |
 | 1-0 | 34 | 1956 | 57th US Open | C86 Ruy Lopez, Worrall Attack |
| 28. J Hudson vs P Lapiken |
| 1-0 | 35 | 1956 | 57th US Open | B07 Pirc |
| 29. P Lapiken vs V Pupols |
| 1-0 | 26 | 1958 | Idaho Open | A16 English |
| 30. P Lapiken vs Rhys W Hays |
| 0-1 | 33 | 1958 | 59th US Open | C02 French, Advance |
| 31. P Lapiken vs Santasiere |
| 0-1 | 35 | 1958 | 59th US Open | A16 English |
| 32. P Lapiken vs J F Shaw |
| 1-0 | 53 | 1958 | 59th US Open | B20 Sicilian |
| 33. P Lapiken vs J Hudson |
| 1-0 | 38 | 1958 | 59th US Open | B20 Sicilian |
| 34. R Weinstein vs P Lapiken |
| ½-½ | 43 | 1958 | 59th US Open | D09 Queen's Gambit Declined, Albin Counter Gambit, 5.g3 |
| 35. J W Collins vs P Lapiken |
| ½-½ | 41 | 1958 | 59th US Open | E53 Nimzo-Indian, 4.e3 |
| 36. P Lapiken vs F Ballbe Anglada |
| 0-1 | 36 | 1958 | 59th US Open | C63 Ruy Lopez, Schliemann Defense |
| 37. P Lapiken vs M Rohland |
| 1-0 | 44 | 1959 | 60th US Open | B22 Sicilian, Alapin |
| 38. J F Shaw vs P Lapiken |
| 1-0 | 36 | 1959 | 60th US Open | E40 Nimzo-Indian, 4.e3 |
| 39. E Hearst vs P Lapiken |
| 1-0 | 22 | 1959 | 60th US Open | C41 Philidor Defense |
| 40. R Vincent vs P Lapiken |
| 1-0 | 34 | 1959 | 60th US Open | B07 Pirc |
| 41. P Lapiken vs A G Murphy |
| 1-0 | 16 | 1959 | 60th US Open | B00 Uncommon King's Pawn Opening |
| 42. P Lapiken vs J Ragan |
| 0-1 | 36 | 1960 | 61st US Open | B45 Sicilian, Taimanov |
| 43. P Lapiken vs J W Collins |
| 1-0 | 37 | 1960 | 61st US Open | B32 Sicilian |
| 44. G Baylor vs P Lapiken |
| 1-0 | 21 | 1960 | 61st US Open | C34 King's Gambit Accepted |
| 45. J Spence vs P Lapiken |
| 0-1 | 37 | 1961 | 62nd US Open | C23 Bishop's Opening |
| 46. P Lapiken vs Benko |
| 0-1 | 30 | 1961 | 62nd US Open | A07 King's Indian Attack |
| 47. R Byrne vs P Lapiken |
| 1-0 | 46 | 1961 | 62nd US Open | E62 King's Indian, Fianchetto |
| 48. P Lapiken vs A Kraus |
| 1-0 | 20 | 1961 | 62nd US Open | C40 King's Knight Opening |
| 49. J G Sullivan vs P Lapiken |
| 0-1 | 35 | 1961 | 62nd US Open | E94 King's Indian, Orthodox |
| 50. P Lapiken vs J E Barry |
| 1-0 | 46 | 1961 | 62nd US Open | D43 Queen's Gambit Declined Semi-Slav |
Kibitzing
