| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 51. P Lapiken vs L Levy |
| 1-0 | 39 | 1961 | 62nd US Open | B01 Scandinavian |
| 52. A Bisguier vs P Lapiken |
| 1-0 | 21 | 1961 | 62nd US Open | C86 Ruy Lopez, Worrall Attack |
| 53. P Lapiken vs Z Kovacs |
| 0-1 | 14 | 1961 | 62nd US Open | B85 Sicilian, Scheveningen, Classical |
| 54. C Hidalgo vs P Lapiken |
| 1-0 | 33 | 1962 | 63rd US Open | C75 Ruy Lopez, Modern Steinitz Defense |
| 55. M Rohland vs P Lapiken |
| ½-½ | 37 | 1962 | 63rd US Open | C73 Ruy Lopez, Modern Steinitz Defense |
| 56. P Lapiken vs R Castle |
| 0-1 | 31 | 1962 | 63rd US Open | C63 Ruy Lopez, Schliemann Defense |
| 57. P Lapiken vs V Radaikin |
| 1-0 | 43 | 1962 | 63rd US Open | B01 Scandinavian |
| 58. G Kane vs P Lapiken |
| 0-1 | 37 | 1962 | 63rd US Open | C86 Ruy Lopez, Worrall Attack |
| 59. T Lux vs P Lapiken |
| 0-1 | 39 | 1962 | 63rd US Open | C82 Ruy Lopez, Open |
| 60. P Lapiken vs A Medina Garcia |
| 0-1 | 88 | 1962 | 63rd US Open | A14 English |
| 61. J G Sullivan vs P Lapiken |
| ½-½ | 43 | 1962 | 63rd US Open | D32 Queen's Gambit Declined, Tarrasch |
| 62. K Merkis vs P Lapiken |
| 1-0 | 34 | 1964 | 65th US Open | D52 Queen's Gambit Declined |
| 63. P Lapiken vs I Zalys |
| 0-1 | 54 | 1964 | 65th US Open | A00 Uncommon Opening |
| 64. J Fisher vs P Lapiken |
 | 0-1 | 42 | 1968 | 69th US Open | A22 English |
| 65. P Lapiken vs K Burger |
| 0-1 | 59 | 1968 | 69th US Open | B09 Pirc, Austrian Attack |
| 66. P Lapiken vs M Rohland |
| 1-0 | 39 | 1968 | 69th US Open | B25 Sicilian, Closed |
| 67. V Seglins vs P Lapiken |
| 1-0 | 15 | 1968 | 69th US Open | C45 Scotch Game |
| 68. H D Wallach vs P Lapiken |
| 1-0 | 33 | 1968 | 69th US Open | D20 Queen's Gambit Accepted |
| 69. P Lapiken vs D Willis |
| 0-1 | 37 | 1969 | 70th US Open | A00 Uncommon Opening |
| 70. E Olins vs P Lapiken |
| ½-½ | 42 | 1969 | 70th US Open | D20 Queen's Gambit Accepted |
| 71. I Zalys vs P Lapiken |
| 1-0 | 44 | 1969 | 70th US Open | C41 Philidor Defense |
| 72. P Lapiken vs A Sildmets |
| 0-1 | 30 | 1969 | 70th US Open | D77 Neo-Grunfeld, 6.O-O |
| 73. Z Kovacs vs P Lapiken |
| 0-1 | 41 | 1971 | 72nd US Open | E41 Nimzo-Indian |
| 74. P Lapiken vs R Martin |
| 1-0 | 37 | 1971 | 72nd US Open | A15 English |
| 75. L Binet Tapaszto vs P Lapiken |
| 1-0 | 30 | 1971 | 72nd US Open | A45 Queen's Pawn Game |
Kibitzing
