India's Viswanathan Anand regained the sole lead with a sparkling victory over former challenger Veselin Topalov from Bulgaria in the ninth round of Candidates Chess tournament on Sunday.
The hard-earned victory proved crucial for five-time World Champion Anand as he took his tally to six points out of a possible nine.
The equations went for a toss in the ninth round as Shakhriayar Mamedyarov defeated top seed Levon Aronian of Armenia and Vladimir Kramnik suffered a shock defeat at the hands of Russian teammate Sergey Karjakin.
The other game between the Russian duo of Dmitry Andreikin and Peter Svidler ended in a draw.
With five rounds still to come, Anand now enjoys a full point lead over Aronian who remained on five points after the debacle.
Kramnik was joined by Karjakin and Mamedyarov on 4.5 points for the joint third spot while Andreikin and Svidler are now joint sixth on four points apiece while Topalov is on the last spot on 3.5 points.
To sum things up, Anand is on a roll and will fancy his chances a great deal now.
It was Anand's day all the way. Up against Topalov's pet Sicilian Najdorf, Anand did not give much away in the opening as white and retained a minuscule advantage as the game entered unchartered territories.
Topalov decided to go for exchanges at regular intervals while his position remained slightly worse and this was not a good strategy as Anand continued to exert pressure when the game reached queen and minor piece endgame.
The Indian picked up a pawn when Topalov erred and handled the remaining technicalities of the queen and pawns endgame in masterly fashion to script his third victory in the tournament.
Mamedyarov played the spoiler for Aronian and continued with his roller-coaster ride in the tournament. After blundering his way against Kramnik in the seventh round game when he mishandled a won position and lost, Mamedyarov made sure he held on to his own after attaining an advantage against Aronian who was out of sorts in this ninth round game.
Mamedyarov won in 44 moves.
Karjakin continued with his comeback act and defeated Kramnik for his second straight victory. Starting with an ultra-safe approach in the opening, Karjakin capitalised on some erroneous play by Kramnik in the middle game to win a handful of pawns. The technicalities thereafter were not difficult to handle.
Results round 9: V Anand (Ind, 6) beat Veselin Topalov (Bul, 3.5); Sergey Karjakin (Rus, 4.5) beat Vladimir Kramnik (Rus, 4.5); Shakhriyar Mamedyarov (Aze, 4.5) beat Levon Aronian (Arm, 5); Dmitry Andreikin (Rus, 4) drew with Peter Svidler (Rus, 4).