World champion Viswanathan Anand dropped out of contention for a top finish in the Bilbao Grand Slam final chess tournament after losing from a better position to Levon Aronian of Armenia in the eighth round.
After suffering his second loss in the tournament, Anand's number one world ranking is under threat, and unless there is a revival in fortunes, the Indian ace stands to lose some precious rating points from the tournament.
On another day of 'bloody battles' former World champion Veselin Topalov scored his second victory over Magnus Carlsen of Norway to regain sole lead while Vassily Ivanchuk's new-found form helped him grind Teimour Radjabov of Azerbaijan.
With just two more rounds remaining in the double round-robin event, with a soccer-like scoring system, Topalov has 14 points. He is followed by Aronian at 12.
Ivanchuk and Carlsen share the third spot with 11 points each while Anand and Radjabov are now distant joint fifth, having just six points each.
The disturbing aspects of Anand's defeat against Aronian were losing with white and misplaying a superior endgame.
It was a Scotch opening that gave Anand slightly better prospects after the queens got traded early and the Indian nursed his position well to reach a better rook and minor piece endgame.
After winning a pawn, disaster struck Anand as he lost control in quick time. Aronian took his chances and turned tables with some deft manoeuvres. It was a bad day in office for the World champion when nothing went right.
Aronian's technique has not been in question for a long time now and he proved why. Queening one of the pawns, the Armenian got the full point in 75 moves.
The Topalov-Carlsen affair was very exciting. The Bulgarian had gone for the King pawn opening unafraid of meeting Carlsen's Dragon, which indeed came on the Board.
Carlsen played a theoretical novelty and he continued to play fast in the early middle game showing deep preparation but Topalov managed to get an advantage anyway with some finely crafted manoeuvres.
Experts started to believe in Carlsen's chances again after Topalov missed a few clear wins, pointed out by the computer, but the Bulgarian proved that the human way was also good enough. The game lasted 42 moves.
Ivanchuk came under tremendous time pressure but the ability to play fast and correct helped him gain a full point against Radjabov in a Sicilian defense game.
With 16 moves to go, Ivanchuk was left with just one minute against two of Radjabov and while both were blitzing out the moves Radjabov made a few inaccuracies and lost an exchange that proved decisive.
Results round 8: V Anand (Ind, 6) lost to Levon Aronian (Arm, 12); Veselin Topalov (Bul, 13) beat Magnus Carlsen (Nor, 11); Vassily Ivanchuk (Ukr, 11) beat Teimour Radjabov (Aze, 6).
Anand vs Aronian
1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Bc5 5. Nxc6 Qf6 6. Qf3 bxc6 7. Nd2 d6 8. Nb3 Bb6 9. a4 a5 10. Bd2 Qxf3 11. gxf3 Ne7 12. Rg1 O-O 13. Be3 Bxe3 14. fxe3 c5 15. O-O-O Bb7 16. Bb5 Bc6 17. e5 Rfd8 18. exd6 cxd6 19. Bxc6 Nxc6 20. Nd2 d5 21. Nb3 c4 22. Nd4 Nb4 23. Nb5 g6 24. Rg4 Rdc8 25. e4 h5 26. Rf4 dxe4 27. Rxe4 Rc5 28. f4 Ra6 29. Rd8+ Kg7 30. Rd7 Rd5 31. Rc7 Na2+ 32. Kb1 Nb4 33. Nd4 Rf6 34. Rxc4 Rg5 35. b3 Rg4 36. Ne2 Rh4 37. Rc5 Rxh2 38. Rxa5 h4 39. Rg5 Rf2 40. Rxb4 Rxe2 41. f5 h3 42. Rh4 h2 43. Kb2 Rc6 44. fxg6 fxg6 45. Ka3 Rcxc2 46. Rg3 Ra2+ 47. Kb4 Re4+ 48. Rxe4 h1 Q 49. Reg4 Qb7+ 50. Ka5 Qd5+ 51. Kb4 Qd6+ 52. Kb5 Qb8+ 53. Ka5 Rf2 54. Rxg6+ Kf7 55. Rg7+ Ke6 56. R7g6+ Kd5 57. R6g5+ Kd4 58. b4 Rf4 59. Rg1 Rf3 60. Rc5 Qa8+ 61. Kb5 Rf6 62. Rd1+ Ke3 63. a5 Qe8+ 64. Kc4 Qa4 65. Rd3+ Ke2 66. Re5+ Kf1 67. Red5 Qc2+ 68. Rc3 Rf4+ 69. Rd4 Qa2+ 70. Kc5 Rf5+ 71. Kb6 Qe6+ 72. Kb7 Rb5+ 73. Kc7 Qe7+ 74. Kc6 Qb7+ 75. Kd6 Rh5 white resigned.