World champion Viswanathan Anand mishandled a winning endgame and drew with former women's world champion Yifan Hou of China in the 11th round of 75th Tata Steel Chess tournament here.
Desperately needing a victory to bridge the gap with tournament leader Magnus Carlsen of Norway, Anand outplayed Yifan right from the opening but a shocking blunder in what appeared to be a winning position cost the Indian an important half point.
Carlsen remained in sole lead after surviving some anxious moments against Wang Hao of China who pressed for a victory against the world number one. The Norwegian took his tally to 8.5 points out of a possible eleven and he is now trailed by Levon Aronian of Armenia who defeated Hikaru Nakamura of United States.
With Aronian on 7.5 points, Anand slipped to sole third spot with seven points in all and now the chances of world champion catching up with tournament leader are absolutely slim.
In other games of the day, P Harikrishna enjoyed a superior endgame but could not convert it in to a full point against Erwin L'Ami of Holland. Another draw took Harikrishna to a respectable 5.5 points in the category-20 super tournament.
The day featured four decisive games in all and reaping rewards was Sergey Karjakin of Russia who defeated Ivan Sokolov of Holland. Another Dutch Loek Van Wely went down to Peter Leko while local star Anish Giri demolished the defenses of Fabiano Caruana of Italy to register his first victory in the tournament.
With just two rounds to come, the tournament looks of academic interest with Carlsen having a full point lead. Anand meets L'Ami in the next round and will be hoping for an improved performance.
It was a Najdorf Sicilian by Anand as black and Yifan went wrong early while trying to launch an offence against the centralised black king. Anand neutralised the initiative and post the trading of queens enjoyed a decent advantage.
A further error by Yifan left her a pawn less and immaculate manoeuvres by Anand quickly led to a winning knight and pawns endgame. However, with the win in sight, Anand made an optical error and found himself in a drawn king and pawns endgame.
Harikrishna also should have won against L'Ami but his technique did not come good in the ensuing minor pieces endgame. L'Ami held his fort together and salvaged a half point.
Results round 11: Yifan hou (Chn, 4) drew with V Anand (Ind, 7); Erwin L'Ami (Ned, 3.5) drew with P Harikrishna (Ind, 5.5); Peter Leko (Hun, 6.5) beat Loek Van Wely (Ned, 5); Anish Giri (Ned, 5) beat Fabiano Caruana (Ita, 4.5); Wang Hao (Chn, 4.5) drew with Magnus Carlsen (Nor, 8.5); Hikaru Nakamura (Usa, 6.5) lost to Levon Aronian (Arm, 7.5); Sergey Karjakin (Rus, 6.5) beat Ivan Sokolov (Ned, 2.5).
The moves: Yifan Hou - V Anand
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 Nbd7 7. Qe2 h6 8. Bh4 g6 9. f4 e5 10. fxe5 dxe5 11. O-O-O Be7 12. Nf3 Qc7 13. Qc4 Qb8 14. Nd5 b5 15. Qc6 Nxd5 16. Rxd5 Qb7 17. Qc3 f6 18. Bf2 Nb6 19. Rd1 Na4 20. Qb3 Qc6 21. Qd5 Qxd5 22. exd5 Bc5 23. Bg3 Nb6 24. Bd3 Bf5 25. Bxf5 gxf5 26. Rhf1 O-O-O 27. Bf2 Bxf2 28. Rxf2 Rxd5 29. g3 Rxd1+ 30. Kxd1 Nd5 31. Nh4 f4 32. Rd2 Ne3+ 33. Ke2 Nc4 34. Rd1 fxg3 35. b3 Rd8 36. Rxd8+ Kxd8 37. hxg3 Nd6 38. Kd3 b4 39. c4 bxc3 40. Kxc3 Kd7 41. Kd3 Ke6 42. b4 Nf5 43. Nxf5 Kxf5 44. a4 Ke6 45. g4 Kd5 46. Kc3 Ke4 47. Kc2 Kd4 48. Kb3 e4 49. b5 axb5 50. axb5 e3 51. Kc2 Ke4 52. Kd1 Kd5 draw agreed.