Norway's Viktor Hovland hit a superb bogey-free seven-under-par 63 to win the PGA Tour's season-ending Tour Championship by five shots in Atlanta.
The 25-year-old led by six going into Sunday's final round but was pressed by Xander Schauffele, who shot a 62 and was three back with six holes to play.
However, Hovland birdied the final three holes to pull clear and win the FedEx Cup trophy and $18m (£14.1m).
"It's pretty surreal to be standing here right now," he said.
Hovland opened with four birdies in his opening six holes to match playing partner Schauffele, who also had a fast start.
The American holed further birdie putts on the eighth, 11th and 12th holes to reduce the deficit to three as Hovland scrambled to make pars.
It looked like the world number five's advantage may be further reduced on the 14th after he hit a poor chip but he sensationally holed a 23-foot putt to save par. A putt he said was "huge for momentum" and allowed him to relax after that.
His fifth birdie of the day came on the 16th, after a run of nine pars, and he added two more on the 17th and 18th to seal the biggest win of his career.
More to follow.
