Chennai: After a sensational third round of the Grand Slam Masters chess tournament at Sao Paulo, World champion Viswanathan Anand and World No. 1 Magnus Carlsen of Norway languished at the bottom of the points table.

Anand bowed to an in-form Vassily Ivanchuk of Ukraine while Carlsen called all the shots against bottom-ranked player
Vallejo Pons of Spain before blundering a piece to leave the tournament in a state of shock before the first rest day.

The football points system ensured that Ivanchuk, with seven points, had a good lead over the rest of the field. Levon Aronian of Armenia was in second position with five points, Hikaru Nakamura of US and Vallejo Pons were further down on three points while tailenders Anand and Carlsen shared the last position with two points each.

Ivanchuk unleashed the Schliemann gambit against the Ruy Lopez and slowly got the initiative as Anand tried to play his usual solid game and lost his way with a dubious pawn push in the centre on move 22. That gave Ivanchuk a pawn but that was not the end of the story as Anand could still defend and take the game to a slightly inferior ending.

Ivanchuk kept the pressure and exchanged the right pieces at the right time to go into a queen and pawn ending where he avoided the perpetuals and promoted his queenside pawn to squeeze the world champion after 69 moves.

If Anand's loss was mainly due to his opponent's hard work, Carlsen enjoyed a good position after he played the Pirc-Kings Indian defence mix perfectly. The Norwegian had got the initiative by move 15 and looked set to crush Vallejo, who hung in for dear life to avoid his third successive defeat.

Then in a moment of madness, Carlsen made a queen move that left him in despair. After the 30th-move blunder, Vallejo was a piece up. By move 42, Vallejo was in a position to promote his kingside pawn. "I got a pleasant position from the opening. He probably played inaccurately at somepoint It became a huge, almost winning advantage," said Carlsen after the game. "At one point I wasted too much time trying to find a forced win. Then, I blundered a piece very simply.

I don't know if you can call it an optical illusion or whatever." Aronian and Nakamura drew in 46 moves of Slav defence in a knight ending to keep their undefeated status in the tournament, which resumes on Friday night.