Jason Dufner overhauled Jim Furyk in the final round to win the US PGA Championship at Oak Hill on Sunday.
The American finished the tournament 10 under, two shots clear of compatriot Furyk after a final-round 68.
Furyk, 43, scored 71 but it wasn't enough to hold onto his overnight lead as Dufner overtook him and then held on for his maiden major title victory.
Swedish golfer Henrik Stenson finished third on seven under, while Rory McIlory showed signs of a return to form - the former winner ended up on three under.
Lee Westwood carded a 76 to leave him four over after the four days of golf. This year's winner, Dufner put paid to the ghosts of 2011, when he lost in a play-off to Keegan Bradley in the same championship.
A two-time PGA Tour winner, Dufner put himself in position to challenge with a stunning 63 on Friday - equalling the lowest score in major history.
Going into the final round at the upstate New York course trailing Furyk by one shot, the 36-year-old was level after a birdie at the fourth, and a string of birdies on the front nine saw him go two shots clear at the turn.
He played almost perfect golf throughout the round, the only blemishes were bogeys on the 17th and 18th but Furyk also struggled on those holes.
"I can't believe this is happening to me," Dufner told BBC Sport. "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, a major winner at the US Open in 2003, will rue the missed opportunity to put pressure on Dufner at the 17th and 18th.
Other notables included Masters winner Adam Scott - the Australian carded a 70 to finish the tournament on five under.
Dufner becomes the 18th different major winner in the last 20 tournaments - a remarkable statistic that underlines the competitiveness of the sport at the moment.
FINAL ROUND LEADERBOARD
-10: J Dufner (US) -8: J Furyk (US) -7: H Stenson (Swe) -6: J Blixt (Swe) -5 : A Scott (Aus), S Piercy (US) Selected: -3: R McIlroy (NI) -2: G McDowell (NI), M Warren (Sco) +3: L Westwood (Eng) +4: T Woods (US) +8: I Poulter (Eng) +12: P Mickelson (US)