[Event "NED-ch26"]
[Site "Leeuwarden"]
[Date "1971.04.08"]
[Round "4"]
[White "Timman, Jan H"]
[Black "Boersma, Paul"]
[Result "1-0"]

1. e4 c5 2. Nf3 d6 3. Nc3 a6 4. g3 Nc6 5. Bg2 g6 6. d4 Bg4 7. dxc5 dxc5 8. Be3 Qa5 9. O-O Nf6 10. Nd5 Bg7 11. Qe1 Qxe1 12. Raxe1 Nxd5 13. exd5 Bxf3 14. Bxf3 Ne5 15. Bg2 Nd7 16. Re2 Bxb2 17. Rb1 Be5 18. Rxb7 Kd8 19. Bh3 f5 20. Bg5 Bd6 21. Re6 Kc8 22. Rb1 Nf8 23. Re2 Ra7 24. Rb6 Kd7 25. g4 h6 26. Bd2 g5 27. gxf5 g4 28. Bg2 Nh7 29. Bxh6 Bxh2+ 30. Kxh2 Nf6 31. Kg1 Rxh6 32. Ree6 Ke8 33. Rxa6 Rxa6 34. Rxa6 Rh5 35. Rc6 Rxf5 36. Rxc5 Rf4 37. c4 Rd4 38. a4 Rd1+ 39. Kh2 Ra1 40. Ra5 1-0