[Event "Interzonal-09b"]
[Site "Petropolis"]
[Date "1973.07.29"]
[Round "5"]
[White "Ivkov, Borislav"]
[Black "Biyiasas, Peter"]
[Result "1/2-1/2"]

1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. d4 O-O 6. Be2 e5 7. Be3 Ng4 8. Bg5 f6 9. Bh4 Nc6 10. d5 Ne7 11. Nd2 Nh6 12. f3 c5 13. a3 Nf7 14. b4 b6 15. Rb1 Kh8 16. Bd3 Ng8 17. Bc2 Bh6 18. Qe2 a6 19. Ba4 Ra7 20. Rb3 Bg5 21. Bf2 f5 22. O-O Nf6 23. bxc5 bxc5 24. Rfb1 Bxd2 25. Qxd2 fxe4 26. Nxe4 Nxe4 27. fxe4 Ng5 28. Re3 Raf7 29. Bg3 h5 30. Bh4 Rf4 31. Bg3 R4f7 32. Bh4 Kg7 33. Bc2 Nf3+ 34. Rxf3 Qxh4 35. Rxf7+ Rxf7 36. Bd3 Bd7 37. Rf1 Rxf1+ 38. Kxf1 Qxh2 39. Qa5 Qf4+ 40. Kg1 Qe3+ 41. Kh2 Kh6 42. Qd8 1/2-1/2