Smyslov_Fan wrote on 07/12/06 at 16:47:19:

Btw: in the line I just quoted, the critical position occurred after 12.Bd2 Bd2+ 13.Nd2. The obvious 13...b5 was known to be bad, so Black usually played 13...b6. My novelty was to play an immediate 13...g5!? I don't remember who played it in a big game, but I think it was one of the Candidates Matches at the time.

Out of curiosity, I did a quick database search.

The game you might be thinking of is:

1. e4 e6 2. d4 d5 3. Nc3 Nf6 4. e5 Nfd7 5. f4 c5 6. Nf3 Nc6 7. Be3 Qb6

8. Na4 Qa5+ 9. c3 cxd4 10. b4 Nxb4 11. cxb4 Bxb4+ 12. Bd2 Bxd2+ 13. Nxd2

g5 14.

Nb2 gxf4 15. Nd3 b6 16. Kf2 Ba6 17. Nf3 Rc8 18. Nxf4 Nc5 19. g3 d3 20. Bxd3

Nxd3+ 21. Nxd3 Qa3 22. Nf4 Qb2+ 23. Kg1 Rc2 24. Qd4 Qa3 25. Ne1 Rb2 26. Rc1

Qxa2 27. Nh5 Qb3 28. Nf6+ Kd8 29. Nxd5 exd5 30. e6 Ke7 31. Rc3 Qb5 32. Rc7+

Kxe6 33. Qe3+ Kf6 34. Qe7+ Kf5 35. Qxf7+ Kg5 1-0 Anand-Dreev, Candidates m7 (6), Madras 1991.

However, it looks like the move was played about 4 years earlier:

1. e4 e6 2. d4 d5 3. Nc3 Nf6 4. e5 Nfd7 5. f4 c5 6. Nf3 Nc6 7. Be3 Qb6

8. Na4 Qa5+ 9. c3 cxd4 10. b4 Nxb4 11. cxb4 Bxb4+ 12. Bd2 Bxd2+ 13. Nxd2

g5 14.

Be2 d3 15. Bh5 Qb4 16. O-O b5 17. Bxf7+ Kxf7 18. Qh5+ Ke7 19. Qxg5+ Ke8 20. f5

bxa4 21. fxe6 Nf8 22. Qg7 Ng6 23. Rac1 Bxe6 24. Rf6 Qb6+ 25. Kh1 Rf8 26. Qxh7

Ne7 27. Rcf1 Rg8 28. Qxd3 Kd7 29. Nf3 Qb2 30. Rg1 Rg4 31. h3 Rh8 32. Qa6 Qb6

33. Qxa4+ Rxa4 0-1 Przewoznik-Skrobek, POL-ch sf, Gdynia 1987.