1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Qb6 8. Qd2 Qxb2 9. Rb1 Qa3 10. f5 Nc6 11. fxe6 fxe6 12. Nxc6 bxc6 13. e5 dxe5 14. Bxf6 gxf6 15. Ne4 Be7 16. Be2 h5 17. c4 f5 18. Rb3 Qa4 19. O-O fxe4 20. Qd1

20. Qc3? Qxa2 21. Bd1 Rf8? (21... Bc5+ 22. Kh1 Rf8 23. Bxh5+ Kd8 24. Rd1+ Bd7 25. Rb7 Bd4 and Black wins) 22. Bxh5+ Kd8 23. Rd1+ Bd7 24. Qe3 Qa5 25. Rb7 Bc5 26. Rdxd7+ Kc8 27. Rdc7+ Kd8 28. Rd7+ ½-½, Kavalek - Fischer, Sousse Interzonal 1967 (the stem game).

20. Qc2 Qa5 (20... Bc5+ 21. Kh1 Bd4 22. Qxe4).

20. Kh1!?.

20... Qa5?

20... Bc5+ 21. Kh1 Bd4 22. Bxh5+ Kd8 23. Rf7 Qxc4 24. Be2 Qc5 25. Qf1 is winning for Black.

21. Bxh5+ Rxh5 22. Qxh5+ Kd8 23. Rd1+ Kc7 24. Qe8

24. Qh7? Qc5+ 25. Kh1 Rb8, Kotzem - Gerold, EU/M ICCF corr 1984 (½-½, 29) and Oren - Levin, SEFER A corr 1997 (0-1, 35).

24... Qc5+ 25. Kh1 Bd6

25... Rb8? 26. Rd7+ Bxd7 27. Qxb8#.

25... Bf6 26. Rh3.

25... e3 26. Rxe3, Djuric - Benderać, Yugoslav Team Championship, Cetinje 1993 (1-0, 47).

26. Rg3

26... Qb6 27. c5!.

1-0

Reference(s): Burning the Midnight Oil, IRLchess, September 24, 2021.