Viswanathan Anand [Images] will return to claim the title from defending champion Alexei Shirov at the annual Torneo Magistral de Ajedrez, Ciudad de Leon chess tournament beginning in Spain on Friday.

Anand, the top seed, will have Shirov leading the draw from the opposite side in the tournament which would be played in the rapid format.

The tournament shed its Advanced Chess format, where players were allowed to use computers, in 2003.

Other players in the fray included teenaged prodigy Magnus Carlsenand FIDE World Champion Rustam Kasimdhzanov.

Anand could play either Carlsen or Kasimdhzanov in the semifinals, which will be four games of rapid chess of 20 minutes plus 10 seconds increments.

In case of a tie, 5-minute blitz games will be played.

In case Anand draws Carlsen in the semi-finals, it will be the first time, Anand will clash with the 13-year-old Norwegian prodigy.

Anand and Shirov have played many times with the Indian beating him in their most high-profile clash in FIDE World Championships final in Tehran in 2000 and in Amber this year.

Anand, who has won a hat-trick of Advanced Chess titles in Leon, said he was expecting a tough tournament this year.

"I feel very comfortable in Leon. Since it is a very dynamic event, you have to start cracking from the word go.

"But this year it will be four games so I think it will be tough as if you notice, most rapid game events seem to be very decisive and mistakes and tension can play a huge role. I think stamina and nerves will be very important," he said.

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