Moscow: Five-time world champion Viswanathan Anand, on Friday, won a nerve-wracking contest against former challenger Veselin Topalov of Bulgaria, in the first round of Candidates Chess, to take early lead here.

With two of the three games ending in draws, Anand is likely to emerge as the sole winner on Day 1 of the biggest event of the year. He can now look forward to the rest of the tournament with confidence, even though he was written off by the pundits.

While luck might have played a pivotal role in Anand's conquest, Topalov went on missing some very refined tactics in the game that might probably be known as the clincher for the future generation.

Anand started off well in his pet Ruy Lopez opening and just when things were looking good for the Indian ace, Topalov came up with a superb pawn sacrifice that was in fact taboo.

Anand went for pawn grabbing which was not correct according to computers, but Topalov missed a super-tactic that involved a Bishop sacrifice in the middle game.

As it happened, Topalov could never come back in the game post the fiasco. The Bulgarian watched as Anand penetrated in the base rank with his rooks, and completed the formalities in familiar fashion. The game lasted 49 moves.

In other games of the day, the all-American and all-Russian duel ended in draws. Hikaru Nakamura took his chances and appeared slightly better against compatriot Fabiano Caruana before the latter neutralised everything and got an easy draw.

Sergey Karjakin of Russia also failed to make an impact against Peter Svidler who seemed at ease in the complexities of a Slav Defence as black.

In-form Hikaru Nakamura appears huge favourite with his back-to-back victories at Gibraltar International and the Zurich Chess Challenge. However, it will be a test of nerves for Nakamura, who is setting his sights for his first World Championship contest.

If the views of the reigning world champion Magnus Carlsen matter, Caruana, Aronian or Karjakin are going to be his likely challenger for the next World Championship match slated in United States in November this year.