(Reuters) - Chess grandmaster Viktor Korchnoi, who defected from the Soviet Union in 1976 and then came within one game of beating arch-rival Anatoly Karpov for the world championship, has died at the age of 85, the Russian Chess Federation said on Monday.
The 1978 showdown in the Philippines between the dissident exile and the model Communist champion was one of the great grudge matches in the history of chess.
Korchnoi, virtually written off by commentators after his opponent surged into a 5-2 lead, fought back to level the scores before a rattled and exhausted Karpov rallied to defeat him in the final game.
Three years later, Karpov won a rematch comfortably by 6-2, but Korchnoi is still considered one of the strongest players to miss out on the world title.
The Russian chess federation paid a generous tribute to the man once considered by Moscow as a pariah, describing him as a "legendary grandmaster" with an enormous will to win.
Korchnoi died in Switzerland, where he lived for 40 years.
"The chess world loses its greatest fighter. RIP Viktor Korchnoi. We learnt so much from you," former world champion Viswanathan Anand of India said on Twitter.
(Reporting by Mark Trevelyan; Editing by Louise Ireland)