Viswanathan Anand continued his roller-coaster ride in the London Chess Classic as he went down to Russian Grandmaster Alexander Grischuk in the sixth round.
After drawing the first three rounds, this was Anand's third decisive result in a row and second where the Indian ace ended on the receiving end.
It turned out to be a costly blow as Anand now finds himself in sole ninth spot in the 10-player round-robin tournament.
Benefitting from his first victory in the tournament, Grischuk joined Anish Giri of Hland, Hikaru Nakamura of United States and Maxime Vachier-Lagrave of France in lead on four points out of a possible seven.
Levon Aronian of Armenia, World champion Magnus Carlsen of Norway, Michael Adams of England and Fabiano Caruana of United States share the fifth spot jointly on 3.5 points each.
With 2.5 points in his kitty, Anand is ahead of Bulgarian Veselin Topalov by a full point but is now in a desperate situation in the $300000 prize money tournament.
On what turned out to be another draw-marred day, again four out of five games ended in draws with only Grischuk and Anand producing a decisive result.
Carlsen continued his hunt for an elusive victory against Giri but did not succeed as black, while Nakamura was surprised by Aronian in the opening and his white pieces came a cropper.
It was a long theoretical discussion between Vachier-Lagrave and Fabiano Caruana that also saw the point being split, while Topalov signed peace with Adams.
Experts believed that Anand could defend an inferior rook and pawns endgame against Grischuk but the post-mortem proved otherwise.
Earlier it was a quiet opening by Grischuk as white and Anand got a playable position easily.
Grischuk capitalised on Anand's mistake in the endgame and scored his second victory against the five-time world champion in as many tournaments.
Earlier in the second edition of the Grand Chess Tour -- the Sinquefield Cup in United States, the Russian had emerged victorious.