[Event "IBM"]
[Site "Amsterdam"]
[Date "1972.??.??"]
[Round "?"]
[White "Donner, Jan Hein"]
[Black "Ivkov, Borislav"]
[Result "1-0"]

1. d4 g6 2. c4 Nf6 3. Nc3 Bg7 4. e4 d6 5. Be2 O-O 6. Bg5 h6 7. Be3 c5 8. d5 b5 9. cxb5 a6 10. bxa6 Bxa6 11. Nf3 Nbd7 12. Bxa6 Rxa6 13. Nd2 Ne5 14. O-O Qa5 15. Qe2 Rb8 16. f4 Neg4 17. Nc4 Qb4 18. Bd2 Nd7 19. e5 dxe5 20. h3 Ngf6 21. fxe5 Nh5 22. Ne4 Qb5 23. a4 Rxa4 24. Rxa4 Qxa4 25. g4 Nxe5 26. Nxe5 Qd4+ 27. Rf2 Qxe5 28. gxh5 Rxb2 29. Qf3 f5 30. Ng3 c4 31. Bf4 Rxf2 32. Kxf2 Qb2+ 33. Ne2 g5 34. Bc1 Qe5 35. Bd2 e6 36. dxe6 Qxe6 37. Bc3 g4 38. hxg4 fxg4 39. Qf4 Bf8 40. Nd4 Bc5 41. Kg3 Qd7 42. Qxg4+ Qxg4+ 43. Kxg4 Kf7 44. Kf5 Bb6 45. Nf3 1-0