World Champion Vishwanathan Anand continued to lead the field after the ninth round of the Morelia-Linares International Chess tournament after splitting points with Grandmaster Levon Aronian with the black pieces in a short but tense game.
However, the Indian saw his lead being reduced to half-a-point as Magnus Carlsen narrowed the gap with a victory over Alexei Shirov, pushing Aronian to the third position.
Grandmaster Veselin Topalov stayed put in the fourth position with a draw against Teimour Radjabov, while Ivanchuk improved his standing by beating Hungarian Grandmaster Peter Leko.
Levon Aronian tried to wrest the lead from Anand by sacrificing a pawn in the opening against the Queens Indian defence. The position became very sharp as Aronian came up with some incisive play and built up a dangerous initiative.
Anand used clever tactics to prevent his opponent from gaining the upper hand. He managed to neutralise Aronian's initiative by giving back the pawn and forcing a position with opposite coloured bishops.
The players decided to split the point on the 27th move in a balanced position.
Norwegian teenager Magnus Carlsen moved to sole second place with a rather lucky victory over Spanish Grandmaster Alexei Shirov.
Carlsen played magnificently with the White pieces in the Spanish opening and gained a clear advantage in the early middle-game. He decided to go for the win of a pawn on the 27th move, which allowed Shirov to activate his pieces.
Carlsen continued to hold the upper hand, but Shirov defended superbly and kept the balance for a long time in the marathon seven hour battle.
The game came to an abrupt end on the 80th move as Shirov blundered away a rook in time trouble and his valiant defense turned out to have been in vain.
Ukranian Grandmaster Vassily Ivanchuk joined Shirov in the fifth position by defeating Grandmaster Peter Leko with the black pieces.
Ivanchuk played the Caro Kann defence and exchanged pieces to nullify his opponent's advantage in space. Leko continued his poor form in this tournament and Ivanchuk managed to infiltrate into the white position with his queen and rook.
His initiative kept increasing and he won with a mating attack in 47 moves.
Veselin Topalov obtained a slightly advantageous position against Teimour Rajdabov with the Spanish opening, but his advantage proved insufficient to win the game.
Topalov kept on testing Radjabov's defensive skill in the major piece ending without making any progress against his opponent's stubborn defense.
Having exhausted all the potential in the position, Topalov conceded a draw in the pawn ending.