Jason Dufner held his nerve to clinch his maiden major title with victory at the US PGA Championship at Oak Hill.
The 36-year-old American overhauled countryman Jim Furyk with a final-round 68 to win by two shots at 10 under.
Furyk, 43, led overnight but 71 was not good enough to add to his 2003 US Open.
Henrik Stenson was third on seven under, with fellow Swede Jonas Blixt six under. Rory McIlroy ended three under after a 70, with Lee Westwood three over after a 76.
The enigmatic Dufner, a two-time PGA Tour winner, came closest to a major title when he squandered a five-shot lead with four to play as he lost to Keegan Bradley in a play-off for the 2011 US PGA title.
But he played imperious golf at Oak Hill on Sunday, hardly hitting a bad shot, to open his major account in upstate New York.
Dufner, who equalled the lowest score in major history with a 63 on Friday, trailed Furyk by one going into the final round, but was sharing the lead with the eight-time Ryder Cup star after a birdie on the fourth and had a two-shot gap after the ninth.
A tentative birdie putt on the 10th, followed by almost missing the next, were virtually the only outward signs of nerves - until both players bogeyed the 17th and 18th - as Dufner maintained his distance on Furyk all the way to the giant Wanamaker trophy.
"I can't believe this is happening to me," said Dufner, who is the 18th different winner in the last 20 majors.
"To come back from a couple of years ago in this championship when I lost to Keegan in the play-off, to win feels really, really good. The last two holes were a little unfortunate. I wish I could've closed out with no bogeys but I am happy to get the job done. It's a big step for my career."
Furyk, who won the last of his 16 titles in 2010, said: "I needed to keep the pedal down and make pars there and keep the pressure on him and I just didn't do it.
"If I could go back I would have to try to make par at 17 and 18 and try to put some heat on him."
Stenson and Blixt were bidding to become the first Swedish man to win a major title, but both had up-and-down days and carded rounds of level-par 70.
For the resurgent Stenson, who dropped from the world's top 10 to as low as 230th in early 2012, it was his fourth straight top-three finish after finishing in a tie for third at the Scottish Open, coming second in the Open and tied-second behind Tiger Woods at Firestone.
Masters champion Adam Scott began four shots adrift but was also unable to make an impression and his 70 left him five under alongside American Scott Piercy, who surged up the leaderboard with a 65.
McIlroy, who missed the cut at the Open to cap a miserable season up to then, was looking likely to miss another cut after 10 holes of his second round. But the Northern Irishman fought back well over the closing stretch to make the weekend and at six shots adrift, he had an outside chance of defending the title he won by a record eight shots at Kiawah Island last year.
The 24-year-old began in promising fashion with a birdie at the third, but a triple bogey via the water on the fifth derailed his challenge and he was always playing catch-up. He salvaged the three shots back with birdies at the ninth, 10th and 13th but a bogey on 16 knocked him back again and he finished in a tie for eighth, his first top 10 in a major this season.
McIlroy's playing partner Westwood also started three under but his 63rd major quickly turned into another without a victory. A bogey at the second and a double bogey at the third set the tone, and three more dropped shots followed to go out in 41. Birdies at 10 and 14 made some amends, but Westwood's putter problems continued and he dropped final shots at the 15th and 18th.
World number one Tiger Woods could only finish tied for 40th at four over after carding rounds of 71,70, 73, 70 - a week after shooting 61 on his way to winning the WGC-Invitational for his fifth title of the year.
The 37-year-old has now gone 18 majors and five years without a major title and will have to wait until the 2014 Masters at Augusta to try to resume his quest for a 15th victory in the tournaments which define careers.
"I've been there in half of them so that's about right. If you are going to be in there in three-quarters or half of them with a chance to win on the back nine, you have just got to get it done," said Woods.
"I was right there and certainly had a chance to win the Masters and the British this year. The other two, I just didn't hit it good enough. Just the way it goes."