[Event "Stockholm Interzonal"] [Site "?"] [Round "0"] [White "Petrosian"] [Black "Bertok"] [Result "1-0"] [ECO "D24"] [Opening "QGA: 4.Nc3 a6"] 1. d4 d5 2. c4 dxc4 3. Nf3 Nf6 4. Nc3 a6 5. e3 e6 6. Bxc4 c5 7. O-O b5 8. Bb3 Bb7 9. Qe2 Nbd7 10. Rd1 Bd6 11. e4 cxd4 12. Rxd4 Bc5 {12...Qb8 13.Rxd6 Qxd6 14. e5 Bxf3 15.Qxf3 Qxe5 16.Bf4 After which White wins the rook on a8.} 13. Rd3 Ng4 {A natural and energetic response to the threat of e5. 13...Qb8 Also gains control of the e5 square.} 14. Bg5 {Developing the bishop with a gain of tempo. } 14... Qb6 {14...Bxf2+ 15.Kf1 Qb6 16.h3 when Black has to many pieces hanging. } 15. Nd5 {A powerful thrust made possible because the Black king hasn't found time to castle.} 15... Qa5 {15...exd5 16.exd5+ Kf8 17.d6 Re8 18.Be7+ Kg8 19. Bxf7+ Kxf7 20.Ng5+ when Black finds himself in a mating net.} 16. Rf1 { Black's only threat is eliminated, and he is left with his king still in the center.} 16... Rc8 17. Nf4 Nge5 18. Nxe5 Nxe5 19. Rh3 { Played with the idea of discouraging Black from castling.} 19... Nc4 20. Rd1 Qb6 21. Nh5 Rg8 {21...O-O would be refuted by 22.Nf6+ gxf6 23.Bxf6 Rfd8 24. Rxh7 Kxh7 25.Qh5+ Kg8 26.Qh8+ Mate.} 22. Rhd3 Nd6 23. e5 Ne4 24. Be3 { 24.Rd8+ Rxd8 25.Rxd8+ Qxd8 26.Bxd8 Kxd8 when Black's active pieces give him the initiative.} 24... Bxe3 25. Rxe3 Qc6 26. Qg4 Ke7 27. Rde1 f5 28. exf6+ gxf6 29. Qh3 {The White queen eyes Black's weak e6-pawn for the final assault on the uncastled king.} 29... f5 30. f3 Ng5 31. Qxf5 Rcf8 32. Rxe6+ Nxe6 33. Rxe6+ Kd8 34. Qd3+ {Black resigned as 34...Qd7 drops the queen to 35. Rd6.} 1-0