BELGRADE, November 18: Vassily Ivanchuk went into sole leadership with a fine win over Alexander Beliavsky, overcoming the latter's Pric defence in just 41 moves of the sixth round of the Investbanka international Grandmasters chess tournament last night.Viswanathan Anand and Alexi Shirov, who shared the lead with Ivanchuk after five rounds, drew their sixth round and were half a point adrift of the leader. Anand had white pieces in a Ruy Lopez which the two agreed to draw after 23 moves.Vladmir Kramnik and Boris Gelfand were engaged in a marathon 66-move draw from a Kings Indian main line, while Kiril Georgiev and Joel Lautier drew in 32 moves following a Sicilian-Najdorf.Results (6th round): Ivanchuk (4.5) bt Beliavsky (2); Anand (4) drew with Shirov (4); Kramnik (3.5) drew with Gelfand (3); Georgiev (2.5) drew with Lautier (3.5); Kovacevic (1) bt Ljubojevic (2)