[Event "Interzonal-10a"]
[Site "Biel"]
[Date "1976.07.13"]
[Round "3"]
[White "Sosonko, Gennadi"]
[Black "Castro Rojas, Oscar Humberto"]
[Result "1/2-1/2"]
[WhiteElo "2505"]
[BlackElo "2380"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Qb3 dxc4 6. Qxc4 O-O 7. e4 Bg4 8. Be3 Nfd7 9. O-O-O c6 10. h3 Bxf3 11. gxf3 b5 12. Qb3 a5 13. d5 a4 14. Qa3 Qa5 15. dxc6 b4 16. Qxa4 Nxc6 17. Qxa5 Rxa5 18. Nb5 Rxa2 19. Rxd7 b3 20. Nc3 Bxc3 21. bxc3 Rb8 22. Kb1 b2 23. Bb5 Ra1+ 24. Kxb2 Rxh1 25. Rd5 e6 26. Rc5 Na7 27. c4 Rxh3 28. Kc3 Nxb5+ 29. Rxb5 Rc8 30. f4 h5 31. Rb1 Rh4 32. Kd4 Kf8 33. c5 Ke8 34. Ke5 Rc6 35. Kf6 Kd7 36. Kxf7 Rg4 37. Kf6 Rg2 1/2-1/2