[Event "Interzonal-09b"]
[Site "Petropolis"]
[Date "1973.08.03"]
[Round "8"]
[White "Ivkov, Borislav"]
[Black "Tan, Lian Ann"]
[Result "1-0"]

1. Nf3 d5 2. c4 c6 3. d4 Nf6 4. Nc3 e6 5. e3 Nbd7 6. Bd3 dxc4 7. Bxc4 a6 8. a4 Bb4 9. O-O O-O 10. Qe2 Qa5 11. Rd1 e5 12. Qc2 exd4 13. Rxd4 Nb6 14. Bd3 h6 15. Na2 c5 16. Rh4 Be6 17. Nxb4 cxb4 18. Bd2 Rfc8 19. Qd1 Nc4 20. Bxc4 Rxc4 21. Rxc4 Bxc4 22. Qe1 Qh5 23. Bxb4 Bd5 24. Nd4 Ng4 25. Bd6 Qg6 26. Bg3 Qe4 27. f3 Qxe3+ 28. Qxe3 Nxe3 29. b3 Bc6 30. Nxc6 bxc6 31. Rc1 Rc8 32. Rc5 Nd5 33. Ra5 Ra8 34. Be1 Kf8 35. b4 Rb8 36. Bg3 Rb6 37. Bf2 Rb7 38. Rxa6 Nxb4 39. Bc5+ Ke8 40. Ra8+ Kd7 41. a5 Rb5 42. Bf8 c5 43. Bxg7 h5 44. h4 f5 45. a6 Ra5 46. Rf8 Rxa6 47. Rxf5 Rc6 48. Rxh5 c4 49. Rb5 Nd3 50. h5 Nf4 51. g3 c3 52. gxf4 c2 53. Bb2 c1=Q+ 54. Bxc1 Rxc1+ 55. Kg2 Rc6 56. Re5 1-0