Gary Anderson defeated Adrian Lewis 7-5 to retain his PDC World Championship crown at Alexandra Palace.
The 45-year-old Scot, who miscounted on three occasions, fought off a valiant fightback from the Englishman in the latter stages.
The first six sets were shared in the first-to-seven encounter, before Anderson took a 5-3 advantage.
Englishman Lewis fought back for 6-5 before Anderson made a superb 170 checkout en route to a £300,000 prize.
Anderson, the world number two, went ahead against the darts in the seventh set and never relinquished the lead.
But his victory could have been easier had he not made three mathematical errors.
At one stage, he had 50 left but bust his score by hitting a treble 20.
Despite averaging 99.26 to his opponent's 100.23, Anderson's greater accuracy on the doubles saw him lift the Sid Waddell Trophy for the second year in succession.
He joined Phil Taylor, Lewis and John Part in winning the tournament at least twice.
"I was playing a good friend of mine and it just never happened," said Anderson, who beat Phil Taylor in a thrilling final last year.
"There were some good darts and some bad ones.
"The way I played and the way Adie played, it killed the game. I'm getting old now so I'll take this.
"It would be lovely to come back for a third but the body is hurting. Us older ones are running out, but I'll plod on."
Lewis, the 30-year-old from Stoke-on-Trent, tasted defeat in the final for the first time after victories in 2011 and 2012, the first of which was against Anderson.
"I thought we were going to a decider until he took out a 170," said Lewis. "He's been the best player and deserves it."