[Event "IBM"]
[Site "Amsterdam"]
[Date "1971.07.28"]
[Round "13"]
[White "Portisch, Lajos"]
[Black "Browne, Walter Shawn"]
[Result "1-0"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 c5 5. Bd3 O-O 6. Nf3 d5 7. O-O dxc4 8. Bxc4 Nc6 9. a3 Ba5 10. Na4 cxd4 11. exd4 h6 12. Qd3 Bc7 13. Nc3 b6 14. Rd1 Bb7 15. b4 Rc8 16. Bb2 Bb8 17. Rac1 Qd6 18. Ba6 Qd7 19. Bxb7 Qxb7 20. d5 exd5 21. Nxd5 Nxd5 22. Qxd5 Nd8 23. Rxc8 Qxc8 24. Ne5 Qc2 25. Nd7 Re8 26. Bxg7 Kxg7 27. Qd4+ Be5 28. Nxe5 Ne6 29. Qa1 Kh7 30. h3 Nf4 31. Re1 Rg8 32. Ng4 Nxh3+ 33. gxh3 h5 34. Qf6 hxg4 35. Qxf7+ Kh8 36. Qf6+ Rg7 37. Qh6+ Qh7 38. Re8+ Rg8 39. Rxg8+ Kxg8 1-0