Jason Dufner beat Ernie Els in a sudden death play-off to win the Zurich Classic of New Orleans, an event which saw Luke Donald regain top spot in the world rankings.
Donald needed a top-seven finish at Avondale to regain pole position from Rory McIlroy - and he got it - finishing third.
However, the winner of the tournament was American Dufner, who edged out Els on the second hole of the play-off to land his first PGA title. Both players finished on 19 under. Graeme McDowell hit a final round 72 for a five under par finish.
Dufner had not won in his previous 163 starts on the US PGA Tour and until this weekend was best remembered for losing a play-off to Keegan Bradley in last year's US PGA Championship.
Els had been a man on the move on the final day in Louisiana as he moved into a share of the lead with overnight leader Dufner.
The South African picked up two birdies and an eagle as he turned in 32, while a birdie on the 11th saw him finish on 19 under par with a 67.
Dufner followed a bogey at the sixth with birdies on seven eight and 10 to card a 70 and take the contest to a play-off - the sixth on the tour this season.
Els had a putt of around six feet to win on the first hole of the play-off but failed to take it - and paid when Dufner rolled in from less than a couple of feet minutes later.
The 35-year-old, who marries fiancee Amanda Boyd next month, said afterwards: "It was a tough day, I'd already put up a good number.
"It's been tough trying to get this first win, so this is a little bit of a monkey off my back."
For Donald, a final round 67 followed efforts of 73, 65 and 66 to see him finish two shots behind Dufner and Els.
Birdies on the third, ninth, 11th, 13th and 18th ensured the Englishman finished on his own at 17 under par.
America's Ryan Palmer and Canada's Graeme DeLaet were tied for fourth on 16 under - Palmer firing a final round 69 and DeLaet finishing with a 71.
Steve Stricker was sixth on 15 under after a 70, with fellow Americans trio Ken Duke (70), Cameron Tringale (71) and John Rollins (72) a shot further back.
Compatriot Justin Rose finished tied for 10th on 13 under after a final round 68, while Greg Owen was four shots back after finishing with a 69.
Scotland's Russell Knox, in contention after a second round 64, finished alongside Owen on nine under after a final round 72, England's Brian Davis was one back after a 70.