The chess world has an undisputed world champion for the first time since 1993, after Russia's Vladimir Kramnik won a reunification match in a tie-break.
The match was dogged by controversy
His match with Bulgaria's Veselin Topalov was tied 6-6 at the end of the scheduled series.
In a tiebreaker series of four rapid-play games, Kramnik won the final one to beat his rival 8.5-7.5 overall.
The match reunified two rival chess organisations which split apart 13 years ago.
The dispute dated from the occasion when Garry Kasparov withdrew from the World Chess Federation.
Veselin Topalov was recognised as the World Chess Champion, and Vladimir Kramnik the Classical World Champion.
As Topalov resigned in the final game, Kramnik stood up and celebrated his victory by clutching his hands above his head, as his team erupted in joyful cheers.
"We are planning to get drunk with my friends today," he said.
Both players - each 31 years old - will be paid $500,000 (£270,000) for taking part in the match, which was held in the Russian republic of Kalmykia.
The match, which lasted three weeks, was seeped in tension, with both sides protesting about the behaviour of the other.
At one point Kramnik was accused of taking too many toilet breaks, and the toilets were locked.