Modern Defense, King's Pawn Fianchetto

GARRI KASPAROV vs. JONATHAN SPEELMAN
Chess World Cup, 1989

1. d4, d6
2. e4, g6
3. c4, e5
4. Nf3, exd4
5. Nxd4, Bg7
6. Nc3, Nc6
7. Be3, Nge7
8. h4 ....

Kasparov decides to attack on the king side.

8. .... h6
9. Be2, f5
10. exf5, Nxf5
11. Nxf5, Bxf5
12. Qd2, Qd7
13. 0-0 ....

Sensing that Black is also set at castling on the queen side, White castles on the king side and prepares to attack on the queen side.

13. .... 0-0-0
14. b4! ....

This little sacrifice goes a long way....

14. .... Nxb4
15. Nb5, Nc2
16. Bf3!!, d5
17. Bxd5, Nxa1

If 17....c6, then 18. Nxa7+ Kb8, 19. Bf4+ Ka8, 20. Qa5 with a mating threat.

18. Nxa7+, Kb8
19.  Qb4 ....

Now, the finale.
 

19. ....  Qxd5

Black has no choice but to sacrifice his Queen.  If 19....b6, then 20. Bxb6 cxb6, 21. Qxb6+ and mate next move.

If 19....c6, then 20. Bf4+ Ka8, 21. Qa3 with a devastating attack.

White clearly wins at this point, but Black fights on.

20. cxd5, Nc2
21. Qa5, Nxe3
22. fxe3, Rhe8
23. Nb5, Rxd5
24. Qxc7+, Ka8
25. Qa5+, Resigns