After three draws Carlsen Needs a win and gets one.
Peter Svidler surprises Aronian by playing Queens Gambit accepted.
Boris Gelfand and Vassily Ivanchuk cannot afford to lose another game, and end in a draw.
So after round four Magnus Carlsen and Levon Aronian lead with 3 points each. They are followed by Peter Svidler, then Teimour Radjabov and Vladimir Kramnik. Alexander Grischuk, Boris Gelfand And Vassily Ivanchuk are down at the bottom.