[Event "Mar del Plata International-27"]
[Site "Mar del Plata"]
[Date "1966.03.26"]
[Round "12"]
[White "Portisch, Lajos"]
[Black "Stein, Leonid"]
[Result "1/2-1/2"]

1. Nf3 Nf6 2. c4 g6 3. g3 Bg7 4. Bg2 O-O 5. d4 c5 6. Nc3 cxd4 7. Nxd4 Nc6 8. Nc2 d6 9. b3 Bf5 10. e4 Bg4 11. Qd2 a6 12. Ne3 Qa5 13. Bb2 Be6 14. O-O b5 15. f4 bxc4 16. f5 Bh6 17. fxe6 Ng4 18. Rf4 Bxf4 19. gxf4 Qc5 20. Re1 fxe6 21. Na4 Qa7 22. bxc4 Nxe3 23. Rxe3 Rxf4 24. c5 dxc5 25. Qc3 e5 26. Qc4+ Kg7 27. Qxc5 Rf6 28. Qxa7 Rxa7 29. Nc5 Nd4 30. Bh3 Rb6 31. Nb3 Rd6 32. Nxd4 exd4 33. e5 Rd8 34. Rd3 Rc7 35. Be6 Rc2 36. Bxd4 a5 37. Bb3 Re2 38. Re3 Rxe3 39. Bxe3 Rc8 40. e6 Ra8 41. Bd4+ Kf8 42. Kf2 a4 43. Bd1 Ra6 44. Bc3 h5 45. Bb4 Rxe6 46. Bxa4 Re4 47. a3 Rh4 48. Kg3 Rg4+ 49. Kh3 Rg1 50. Bc6 g5 51. Bd2 Ra1 52. Bxg5 Rxa3+ 53. Kh4 Ra5 54. Bh6+ Kf7 55. Bf3 Kg6 1/2-1/2