[Event "IBM"]
[Site "Amsterdam"]
[Date "1961.??.??"]
[Round "7"]
[White "Tan, Hiong Liong"]
[Black "Donner, Jan Hein"]
[Result "1-0"]

1. c4 Nf6 2. Nc3 g6 3. d4 Bg7 4. Bg5 d6 5. e3 Nbd7 6. Be2 c6 7. Nf3 h6 8. Bh4 g5 9. Bg3 Nh5 10. Qc2 Nxg3 11. hxg3 e6 12. O-O-O Nf6 13. Nd2 Qe7 14. f4 Bd7 15. e4 O-O-O 16. e5 Ne8 17. Bh5 gxf4 18. gxf4 f6 19. Nf3 fxe5 20. dxe5 dxe5 21. fxe5 Bxe5 22. Nxe5 Qg5+ 23. Qd2 Qxe5 24. Bxe8 Rhxe8 25. Rxh6 Re7 26. Rh4 Rg8 27. Rd4 Qg5 28. Ne4 Qxd2+ 29. R1xd2 Rf8 30. Nc5 Rf1+ 31. Rd1 Rxd1+ 32. Rxd1 Be8 33. b3 Bg6 34. Kd2 Bf5 35. Ke3 Rg7 36. Rd2 Rg4 37. Kf3 b6 38. Nd7 c5 39. Ne5 Rg7 40. Kf4 Kc7 41. g4 Bh7 42. g5 Bf5 43. Rg2 Bg6 44. Nxg6 Rxg6 45. Rd2 Rg7 46. Kg4 Rg8 47. Kh5 Rh8+ 48. Kg6 Rh3 49. Kf6 Rg3 50. g6 e5 1-0