Wijk Aan Zee: Indian grandmaster Viswanathan Anand's quest for a record sixth title suffered a setback as he slumped to a shock defeat against Vladimir Kramnik of Russia in the seventh round of the Tata Steel Masters chess tournament, here.

Having done quite well so far, Anand went for unwarranted complications against Kramnik who was at his best to match his opponent.

The Italian opening by the Indian became very complicated when Anand decided to keep his king in the middle of the board and Kramnik showed deep understanding in finding the right manoeuvres.

As it happened in the game, Anand's king proved to be under more danger than the counterpart and Kramnik skillfully deployed his forces to carve out a fine victory in 36 moves.

The loss proved costly as Anand slipped to joint sixth spot from his overnight joint second position.

Shakhriyar Mamedyarov of Azerbaijan stretched his lead to a full point after his third straight victory in the tournament.

On the receiving end was Wei Yi of China who was outdone from a Catalan opening where the former played white.

Top rated Magnus Carlsen was stretched but eventually converted a full point against Yifan Hou of China, the highest ranked woman player.

With six rounds still to come, Mamedyarov is sitting pretty on 5.5 points out of a possible seven and is now followed by Anish Giri of Holland, Wesley So of United States, Carlsen and Kramnik who all have 4.5 points each.

Anand, on four, shares the sixth position along with Sergey Karjakin of Russia.

The other Indian in the masters – B Adhiban played out a draw with Maxim Matlakov of Russia to inch his tally up to 1.5 points. Adhiban has suffered four losses and drew the remaining three games thus far.

In the challengers section, grandmaster Vidit Gujrathi was again held to a draw by Lucas Van Foreest of Holland.

The Indian took his tally to five points in all and remained a full point behind tournament leader Anton Korobov of Ukraine who also split the point in his seventh round game.

D Harika was close to equalising but went down fighting against Germany's Matthias Bluebaum.

Results after round 7 Masters: Viswanathan Anand (IND, 4) lost to Vladimir Kramnik (RUS, 4.5); Maxim Matlakov (RUS, 3.5) drew with B Adhiban (IND, 1.5); Shakhriyar Mamedyarov (AZE, 5.5) beat Wei Yi (CHN, 2.5); Wesley So (USA, 4.5) drew with Anish Giri (NED, 4.5); Sergey Karjakin (RUS, 4) beat Fabiano Caruana (USA, 2); Gawain Jones (ENG, 3.5) drew with Peter Svidler (RUS, 3.5); Magnus Carlsen (NOR, 4.5) beat Hou Yifan (CHN, 1).

Challengers: Vidit Gujrathi (IND, 5) drew with Lucas van Foreest (NED, 4); D Harika (2.5) lost to Matthias Bluebaum (GER, 3.5); Michal Krasnekow (POL, 3) drew with Anton Korobov (UKR, 6); Bassem Amin (EGY, 3) drew with Jeffery Xiong (USA, 3); Aryan Tari (NOR, 3.5) beat Olga Girya (RUS, 2.5); Jorden van Foreest (NED, 3) drew with Benjamin Bok (NED, 3); Erwin L'Ami (NED, 3.5) drew with Dmitry Gordievsky (NED, 3.5).