[Event "Las Vegas National op"]
[Site "Las Vegas"]
[Date "1973.03.12"]
[Round "1"]
[White "Szabo, Laszlo"]
[Black "Irwin, Philip R"]
[Result "1-0"]

1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. d4 O-O 6. h3 c5 7. Be3 Na6 8. d5 Nc7 9. Be2 a6 10. a4 Rb8 11. a5 b5 12. axb6 Rxb6 13. Ra2 Nd7 14. O-O Rb8 15. Qd2 f5 16. Bh6 fxe4 17. Nxe4 Nf6 18. Bxg7 Nxe4 19. Qe3 Kxg7 20. Qxe4 e5 21. dxe6 Bxe6 22. Rd1 Qf6 23. Rxd6 Rxb2 24. Rxb2 Qxb2 25. Rc6 Rf7 26. Qe5+ Qxe5 27. Nxe5 Re7 28. Rxc5 Bf5 29. Ra5 Ne6 30. Nc6 Re8 31. Rxa6 Nc7 32. Ra7 Rxe2 33. Rxc7+ Kh6 34. c5 Rc2 35. Nd4 Rc1+ 36. Kh2 Be4 37. Re7 Bd5 38. c6 Rc4 39. c7 Bb7 40. Ne6 Bc8 41. Nf8 1-0