Viswanathan Anand defended skilfully as he split the point with Hungarian GM Peter Leko to remain in lead after the sixth round of the World Chess Championship in Mexico City.
The draw, however, allowed Israeli Grandmaster Boris Gelfand to catch up with Anand at the top after beating Russian Grandmaster Alexander Morozevich.
Anand and Gelfand have four points from six games and have a slender half-point lead over their nearest rivals.
Anand faced the Spanish Opening in his game against Peter Leko and he replied with the Archangelsk variation. He sacrificed a pawn in the opening but Leko returned it in a couple of moves in an attempt to wrest the initiative.
The position looked dangerous for Anand but the Indian Grandmaster defended skillfully to neutralise all the threats. The players agreed to split the point after 21 moves in an equal position.
Gelfand was the only winner in the sixth round. Defending Champion Vladimir Kramnik had to be content with a draw against Levon Aronian and Alexander Grischuk split the point against Peter Svidler.
Gelfand continued his superb form and played the solid finachetto variation against the Queens Indian defence and obtained the better endgame after exchange of queens on the 17th move.
Morozevich is not a player who likes to defend quietly and he reacted in his usual style by sacrificing an exchange to create complications.
