Fischer vs Spassky 1972 World Championship, Game 6
Info from Wiki follows:
The World Chess Championship 1972 was a match between challenger Bobby Fischer of the United States and defending champion Boris Spassky of the Soviet Union for the World Chess Championship. The match took place in the Laugardalshöll arena in Reykjavík, Iceland and has been dubbed the Match of the Century.
Fischer became the first American to be the official World Champion since Steinitz (the first Champion) became a naturalized American citizen in 1888. Fischer's win also ended 24 years of Soviet domination of the World Championship.
... In game 6 : After this game, Spassky joined the audience in applauding Fischer's win. He later called it the best game of the match. This win gave Fischer the lead for the first time in the match.[