[Event "San Antonio"]
[Site "San Antonio"]
[Date "1972.11.21"]
[Round "3"]
[White "Byrne, Donald"]
[Black "Portisch, Lajos"]
[Result "1/2-1/2"]

1. g3 e5 2. c4 Nf6 3. Nc3 Bb4 4. Bg2 O-O 5. e4 Nc6 6. Nge2 Bc5 7. O-O d6 8. d3 a6 9. h3 Rb8 10. a3 b5 11. b4 Ba7 12. Nd5 Nxd5 13. cxd5 Ne7 14. d4 f5 15. dxe5 dxe5 16. Qb3 Kh8 17. Be3 Bxe3 18. fxe3 fxe4 19. Nc3 Bb7 20. Rxf8+ Qxf8 21. Bxe4 Ng8 22. Bg2 Nf6 23. e4 Qd6 24. Kh2 h6 25. Qb2 Rf8 26. Qe2 Qb6 27. Rf1 Bc8 28. Rf3 Bd7 29. Nd1 Re8 30. Nf2 a5 31. Qb2 axb4 32. axb4 Qd6 1/2-1/2