Norway's Magnus Carlsen has successfully defended the World Chess Championship after a dramatic day of tiebreak games in New York City.
The initial 12-game series between the champion and Russian challenger Sergey Karjakin ended level at 6-6, meaning four games of rapid chess were played to decide a winner.
These were played at the rate of 25 minutes per player, per game, with 10 seconds added after each move.
Carlsen won two of the games, sealing his first victory in the third after a Karjakin blunder.
Both of the openers had been draws and the Russian then needed to win the fourth to stay alive.
He could not do so, with Carlsen making sure of glory with a stylish queen sacrifice to ensure a devastating checkmate.
The Norwegian had double cause for celebration as today is his 26th birthday.
Both players had won once during the regulation series, with Karjakin taking control by claiming the first victory in game eight.
Carlsen forced a victory in game 10 with the remaining matches all ending as draws.
If rapid chess had not separated the duo, up to five two-game matches of blitz chess would have been played with even less time on the clock.
The final tiebreaker would have been an "armageddon" game where white is given five minutes per move and black only four.
Black, however, would only have needed to draw to be granted a victory, with the format thus guaranteeing a winner.
Carlsen now takes 60 per cent of the $1.1 million (£871,000/€1.03 million) prize-fund.