With just two rounds to go, Norwegian Magnus Carlsen opened up the tournament again with a thumping victory over leader Alexander Grischuk of Russia.

After the end of the 12th round, Grischuk remained in sole lead on seven points, half a point ahead of Carlsen and Ivanchuk, while Anand, on six points, shares the fourth spot along with Levon Aronian of Armenia, who also played out a draw with Chinese Wang Yue (5.5 points) on Friday.

The other game of the day also ended in no result after Azerbaijani Teimour Radjabov (5.5) failed to break the ice against Lenier Dominguez (five points) of Cuba.

Anand could not do much even as he changed gears and came back to his first love - the king pawn opening - for the first time in the tournament.

Ivanchuk surprised his Indian counterpart early by going for the Berlin defense and after a theoretical battle, the Ukrainian equalised comfortably.

"At some point we reached a position when neither side could improve, I took my only chance but he found the right defence," Anand said after both the players agreed for a draw in 32 moves.

Meanwhile, in the game between Carlsen and Grishuk, the Norwegian Grandmaster was at his best in posing problems to black on the queen side in a Scheveningen set up where Grischuk played black.

Carlsen capped his advantage with a temporary exchange sacrifice that strengthened his passed pawn and later came with a superb Bishop sacrifice to march his pawns to glory in 37 moves.

"I guess I had a very good position in the middle game, he could have defended better but it was very difficult for him anyway," Carlsen said after the match.

In another 12th round game, Aronian converted to a Panov-Botwinnik attack after starting with the English opening against Wang Yue but the Chinese appeared well-armed to tackle the intricacies.

The middle game featured routine manoeuvres till Aronian went for a king side attack and even though he won a pawn, black always had sufficient counter play. The peace was later signed in 31 moves.

The longest game of the day was between Radjabov and Dominguez. The Azerbaijani tried hard to break the defenses of Dominguez but did not succeed.

It was a Sicilian Alapin, a rare guest at top level games, that gave Radjabov some hopes as he entered a pawn plus rook and knight endgame but Dominguez stuck to his task and kept white forces at bay to sign peace in 65 moves.