Viswanathan Anand [Images] scored a sensational win over Russian Grand Master Alexander Grischuk in the seventh round to shoot back into sole lead at the World Chess Championship in Mexico City.

Anand outplayed Grischuk in a game that for most part seemed headed for a draw.

With a breakthrough on his 31st move, Anand sacrificed his pawn to carve out a victory in 50 moves and take his tally to five points from seven games. Anand has won three of his seven games and drawn the other four.

Anand's nearest rival, Boris Gelfand, who briefly shared the lead with the Indian ace, failed to score over Vladimir Kramnik and fell half a point behind Anand. Gelfand is at 4.5 points and Kramnik had four.

With the first half of the tournament belonging World No. 1, Anand, it now remains to be seen if he can maintain the tempo in the second half.

Gelfand seemed to go all out with a relentless attack on Kramnik�s position throughout the game. But towards the end, the grip loosened and Kramnik escaped with a draw. Gelfand accepted the draw in the 40th move.

A little later, Anand completed his win over Grischuk to overtake Gelfand and become the sole leader. Grischuk has got 3.5 points at the first half of the tournament.

Peter Leko, still looking for his first win drew with Alexander Morozevich in 60 moves.

Peter Svidler and Levon Aronian played a draw in their seventh round game. Svidler has no wins so far ands has lost twice for 2.5 Aronian has three points from four draws and his win over Peter Leko.

Results of Round 7: Anand beat Grischuk; Kramnik drew with Gelfand; Svidler drew with Aronian; Morozevich drew with Leko

Standings after Round 7: 1. Anand 5 points; 2. Boris Gelfand, 4.5; 3. 3. Vladimir Kramnik 4; 4. Grischuk 3.5; 5. Leko and Aronian 3 points; 7. Morozevich and Svidler 2.5.

Anand v Grischuk

1.e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 O-O 8. a4 b4 9. d3 d6 10. Nbd2 Na5 11. Ba2 c5 12. c3 Nc6 13. d4 bxc3 14. bxc3 exd4 15. cxd4 Nb4 16. Bb1 Bg4 17. h3 Bh5 18. g4 Bg6 19. d5 Nd7 20. Nc4 Rb8 21. Bf4 Nb6 22. Nxb6 Rxb6 23. Nd2 Bg5 24. Bxg5 Qxg5 25. Nc4 Rbb8 26. Qd2 Qxd2 27. Nxd2 f6 28. Nc4 Rfd8 29. f4 Bf7 30. Ra3 g5 31. h4 gxf4 32. Rf3 Be8 33. Rxf4 Kg7 34. h5 Bxa4 35. h6+ Kxh6 36. Rxf6+ Kg7 37. g5 Rf8 38. Rxd6 Bc2 39. Ne5 Rf4 40. Rf6 Rh4 41. d6 Bxb1 42. Rxb1 Rxe4 43. Rf7+ Kg8 44. Re7 Rd8 45. Rd1 c4 46. d7 Rf4 47. Rf1 Rff8 48. Rxf8+ Kxf8 49. Rxh7 c3 50. Ng6+ 1-0

• Complete chess coverage