What is the maximum number of promoted pawns ever achieved in a competitive game? In theory, a player could advance all eight of their pawns to the end of the board, promoting them all. In my own experience, games with more than two promotions on one side have been vanishingly rare, and getting two promotions has been uncommon.

Has a player ever actually promoted all eight of their pawns? If not, what's the maximum number of pawn promotions that a player has achieved in regular competitive play?
In Tim Krabbe’s chess records, Krabbe gives a game where the Black player promoted four of their pawns, the most one player has ever gotten in a professional game, and only one where it has happened. It is also notable for being one of few games with 6 promotions.

The game can also be viewed here at ChessDB.com.

[Title "Alena Kubikova-Vaclav Novy, 9th Open, Czech Republic, 2003"]
[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3  g6 6. Be3 Bg7 7. f3 O-O 8. Qd2  Nc6 9. Bc4 Bd7 10. O-O-O Rc8 11. Bb3 Ne5 12. h4 h5 13. Kb1 a5 14. Bg5 Rc5 15. g4  hxg4 16. f4 Nc4 17. Bxc4 Rxc4 18. e5 Bc6 19. Nxc6 Rxc6 20. exf6 exf6 21. Nd5  fxg5 22. hxg5 Rc5 23. Nf6+ Bxf6 24. Qh2 Re8 25. Qh7+ Kf8 26. gxf6 Qxf6 27. Qh8+  Ke7 28. Rde1+ Re5 29. Qxf6+ Kxf6 30. fxe5+ dxe5 31. Kc1 Kg5 32. Rh7 f5 33. Rxb7  g3 34. Kd2 Kg4 35. Rb3 f4 36. c4 e4 37. c5 e3+ 38. Kd3 Rd8+ 39. Ke4 g2 40. c6 e2  41. c7 Rc8 42. Rc3 f3 43. Ke3 Kg3 44. Rc5 Re8+ 45. Kd2 Kf2 46. c8=Q Rxc8 47.  Rxc8 g1=Q 48. Rxg1 Kxg1 49. Rc1+ Kf2 50. b3 g5 51. a3 g4 52. b4 axb4 53. axb4 g3  54. b5 g2 55. b6 g1=Q 56. Rxg1 Kxg1 57. b7 f2 58. b8=Q e1=Q+ 59. Kc2 Qe2+ 60.  Kc3 Qe3+ 61. Kb4 f1=Q


Regarding informal OTB games, however, 5 promotions is the most that I currently know of from this game.

[Title "Manuel Matto-Anastasia Mossiaguine, Gibraltar Chess Festival, Gibraltar England"]
[FEN ""]

1. e4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. Bc4 Bb4 5. d3 O-O 6. a3 Ba5 7. Bd2 d6 8. h3 Bd7 9. b4 Bb6 10. Bg5 h6 11. Be3 Bxe3 12. fxe3 a6 13. O-O Qe7 14. Qe1 Ne8 15. Nd5 Qd8 16. Qg3 Nf6 17. Nxf6 Qxf6 18. Nh4 Qe7 19. Ng6 Qe8 20. Nxf8 Qxf8 21. Rxf7 Qxf7 22. Bxf7+ Kxf7 23. Rf1+ Kg8 24. Qg6 Kh8 25. Rf7 Rg8 26. Rxd7 b5 27. Rxc7 Nb8 28. Qxd6 Kh7 29. Qxe5 Kh8 30. Rxg7 Rxg7 31. Qxb8+ Kh7 32. Qb6 Rg6 33. Qxg6+ Kxg6 34. Kf2 Kf6 35. d4 Ke6 36. Kf3 Kf6 37. Kf4 h5 38. g4 h4 39. c3 Kg6 40. Ke5 Kf7 41. Kd5 Ke7 42. Kc6 Kd8 43. Kb6 Kc8 44. Kxa6 Kc7 45. Kxb5 Kd6 46. c4 Ke6 47. Kc5 Kf6 48. Kd5 Kg6 49. Ke5 Kh6 50. Kf5 Kg7 51. Kg5 Kf7 52. Kxh4 Kg6 53. e5 Kf7 54. d5 Ke7 55. c5 Kd7 56. b5 Kc7 57. a4 Kb7 58. a5 Ka7 59. e4 Kb7 60. a6+ Kc7 61. b6+ Kd7 62. c6+ Ke7 63. d6+ Kf7 64. Kg5 Kg7 65. e6 Kh7 66. Kf6 Kg8 67. g5 Kf8 68. h4 Ke8 69. h5 Kf8 70. g6 Kg8 71. h6 Kh8 72. a7 Kg8 73. b7 Kf8 74. c7 Ke8 75. d7+ Kf8 76. e7+ Kg8 77. e5 Kh8 78. e6 Kg8 79. e8=N Kh8 80. e7 Kg8 81. a8=R Kh8 82. b8=B Kg8 83. c8=R Kh8 84. d8=N Kg8 85. Ng7 Kh8 86. Be5 Kg8 87. h7+ Kh8 88. Nf7+