Sokolov as black played the Schliemann variation of the Ruy Lopez and surprised the world champion with his choice of opening and drewAnand.
Magnus Carlsen of Norway used this opportunity to defeat Sergey Karjakin of Russia and move back into sole lead with six points from
Anand is in second place on 5.5 points. Aronian and Nakamura are on five points. A further half point behind on 4.5 are Harikrishna and Karjakin.
In a level opposite colour bishop ending, Carlsen stretched with risky pawn breaks to defeat Karjakin in 92 moves. Five rounds remain to be played in this 14-player all-play-all.
The results (round eight): A Giri (Ned) 3 drew with Wang Hao (Chn) 3.5; V Anand (Ind) 5.5 drew with I Sokolov (Ned) 2.5; L Aronian (Arm) 5 bt Hou Yifan (Chn) 2.5; M Carlsen (Nor) 6 bt S Karjakin (Rus) 4.5; L Van Wely (Ned) 3.5 drew with K Nakamura (USA) 5; P Harikrishna (Ind) 4.5 drew with P Leko (Hun) 4; F Caruana (Ned) 4 bt E L’Ami (Ned) 2.5.