Sicilian Defense, Kan. Polugaevsky Variation

VISWANATHAN ANAND vs. KIRIL NINOV
Baguio City, Philippines, 1987

1. e4, c5
2. Nf3, e6
3. d4, cxd4
4. Nxd4, a6
5. Bd3, Bc5
6. Nb3, Ba7
7. Nc3, Nc6
8. Qe2, d6
9. Be3, Bxe3
10. Qxe3, Nf6
11. g4, b5

If 11....Nxg4, 12. Qg3!, White has the advantage.

12. 0-0-0, 0-0
13. g5!, Ne8
14. f4, b4
15. Ne2, a5
16. Nbd4, Nxd4
17. Nxd4, Qb6
18. d5, Bb7
19. Rhf1, dxe5
20. fxe5, Rd8
21. Bxh7+!! ....

A beautiful Bishop sacrifice.  It also protects the Knight at d4.

21. .... Kxh7
22. g6+!!, Kg8

If 22....Kxg6, then 23. Qd3+ f5, 24. exf6+ Kf7, 25. fxg7+ Kxg7 26. Qg3+ wins the Rook. 

23. Qh3, Nf6

If 23....fxg6, then 24. Rxf8+ Kxf8, 25. Nxe6+ followed by 26. Rxd8!

24. exf6, fxg6
25. fxg7, Resigns

The threat is Qh8 mate.  If 25....Kxg7, then 26. Nxe6+ Kg8, 27. Rxd8 Rxd8, 28. Nxd8 Qxd8, 29. Qxe6+ Kh8, 30. Qxg6, and White develops a mating attack.

Fabulous!