| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. C Poulsen vs J Nielsen |
| 0-1 | 45 | 1935 | Danish Championship | D05 Queen's Pawn Game |
| 27. E Andersen vs J Nielsen |
| 1-0 | 7 | 1935 | Danish Championship | D32 Queen's Gambit Declined, Tarrasch |
| 28. J Nielsen vs P Trifunovic |
| ½-½ | 69 | 1935 | Warsaw Olympiad | A84 Dutch |
| 29. H Friedmann vs J Nielsen |
| ½-½ | 37 | 1935 | Warsaw Olympiad | A00 Uncommon Opening |
| 30. J Nielsen vs H Mueller |
| 0-1 | 28 | 1935 | Warsaw Olympiad | E58 Nimzo-Indian, 4.e3, Main line with 8...Bxc3 |
| 31. J Nielsen vs I Pleci |
| ½-½ | 30 | 1935 | Warsaw Olympiad | E43 Nimzo-Indian, Fischer Variation |
| 32. I Solin vs J Nielsen |
| 1-0 | 34 | 1935 | Warsaw Olympiad | D08 Queen's Gambit Declined, Albin Counter Gambit |
| 33. M Luckis vs J Nielsen |
| 1-0 | 50 | 1935 | Warsaw Olympiad | D02 Queen's Pawn Game |
| 34. M Czerniak vs J Nielsen |
| 1-0 | 37 | 1935 | Warsaw Olympiad | D00 Queen's Pawn Game |
| 35. J Nielsen vs I Raud |
| ½-½ | 42 | 1935 | Warsaw Olympiad | D69 Queen's Gambit Declined, Orthodox Defense, Classical, 13.de |
| 36. S Erdelyi vs J Nielsen |
 | 0-1 | 17 | 1935 | Warsaw Olympiad | D08 Queen's Gambit Declined, Albin Counter Gambit |
| 37. J Nielsen vs Szabo |
| ½-½ | 69 | 1935 | Warsaw Olympiad | E47 Nimzo-Indian, 4.e3 O-O 5.Bd3 |
| 38. J Nielsen vs E Andersen |
| 0-1 | 40 | 1935 | Copenhagen Championship | E48 Nimzo-Indian, 4.e3 O-O 5.Bd3 d5 |
| 39. K Ruben vs J Nielsen |
| ½-½ | 38 | 1935 | Copenhagen Championship | D02 Queen's Pawn Game |
| 40. J Nielsen vs A Desler |
| 0-1 | 33 | 1935 | Copenhagen Championship | E32 Nimzo-Indian, Classical |
| 41. J Gemzoe vs J Nielsen |
| 1-0 | 40 | 1935 | Copenhagen Championship | A04 Reti Opening |
| 42. J Nielsen vs H Norman-Hansen |
| 1-0 | 51 | 1935 | Copenhagen Championship | E30 Nimzo-Indian, Leningrad |
| 43. J Nielsen vs P Hage |
| 0-1 | 36 | 1935 | Copenhagen Championship | D66 Queen's Gambit Declined, Orthodox Defense, Bd3 line |
| 44. A Pritzel vs J Nielsen |
| 0-1 | 31 | 1935 | Copenhagen Championship | C64 Ruy Lopez, Classical |
| 45. L Laursen vs J Nielsen |
| 0-1 | 38 | 1936 | DEN-ch | C64 Ruy Lopez, Classical |
| 46. H Mueller vs J Nielsen |
| ½-½ | 41 | 1936 | non-FIDE Munich Olympiad | D60 Queen's Gambit Declined, Orthodox Defense |
| 47. Kostic vs J Nielsen |
 | 1-0 | 18 | 1936 | non-FIDE Munich Olympiad | C45 Scotch Game |
| 48. N Voinov vs J Nielsen |
| 0-1 | 35 | 1936 | non-FIDE Munich Olympiad | A02 Bird's Opening |
| 49. O Trompowsky vs J Nielsen |
| 1-0 | 24 | 1936 | non-FIDE Munich Olympiad | D50 Queen's Gambit Declined |
| 50. J Nielsen vs Barcza |
| 0-1 | 48 | 1936 | non-FIDE Munich Olympiad | D55 Queen's Gambit Declined |
Kibitzing
