[Event "Candidates qf Spassky-Portisch +1-1=12"]
[Site "Mexico City"]
[Date "1980.04.??"]
[Round "4"]
[White "Portisch, Lajos"]
[Black "Spassky, Boris Vasilievich"]
[Result "1/2-1/2"]
[WhiteElo "2655"]
[BlackElo "2615"]

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 c5 5. Bd3 d5 6. Nf3 O-O 7. O-O Nc6 8. a3 Bxc3 9. bxc3 dxc4 10. Bxc4 Qc7 11. Bb5 a6 12. Be2 e5 13. Bb2 e4 14. Nd2 Bf5 15. a4 Rfd8 16. Qc2 Rac8 17. Rfc1 cxd4 18. cxd4 Nxd4 19. Qxc7 Nxe2+ 20. Kf1 Nxc1 21. Qb6 Nd5 22. Qa5 Nd3 23. Bd4 N3b4 24. Nc4 Nc6 25. Qd2 Be6 26. Na3 Ndb4 27. a5 Nxd4 28. exd4 Nd5 29. Rc1 h6 30. Rc5 b6 31. axb6 Nxb6 32. Rxc8 Rxc8 33. h3 Nd5 1/2-1/2