Colombian Camilo Villegas landed the Honda Classic title at Palm Beach in Florida after holding off a Justin Rose-led European challenge as Australian Nathan Green crumbled on the final day.
Green, who started the day second overall, capitulated to close with a 77 that left him joint 12th on one-under-par.
The 34-year-old's fourth round included three bogeys a double-bogey and a triple-bogey at the 17th.
Rose shot a sparkling six-under-par 64 in his final round to jump to third place on seven under for the tournament, and fellow Englishman Paul Casey finished a shot behind in a share of fourth place with Fiji's Vijay Singh.
However Villegas was not prepared to let his hard-earned lead slip away and he won by five shots from second-placed American Anthony Kim, landing his third PGA Tour title and a million-dollar pay day.
Villegas did drop three strokes in five holes on the back nine, however he finished in style with a long putt for birdie at the 18th to card a round of 68 and a total of 13 under for his week.
That score put him five shots in front of Kim, who followed up yesterday's disappointing 73 with a much-improved 67.
Villegas, who began the week promoting a Nationwide Tour event in his homeland, said on Sky Sports: "It's been a long week but it's been a good one and I've loved every second of it."
Rose's round equalled the course record and contained seven birdies, of which five came in his first six holes.
However due to his slow start to the tournament - he was two over par after his opening two rounds - he had left it too late to get close to Villegas.
However, Rose's performance was not enough to qualify him for this week's CA world championship in Miami. The former European number one remains outside the world's top 50.
Casey, who followed his opening 73 with a second-round 64, again went under par today with a classy 67 which included four birdies in five holes from the 12th to 16th.
Singh's challenge faltered as he made bogeys at 15, 16 and 17 in a two-over round of 72.
Sweden's Fredrik Jacobson shared sixth place with American Michael Connell after carding 69 for the fourth successive round.
England's Lee Westwood also tied down a top-10 finish, sharing ninth with Zimbabwe's Brendon de Jonge and American Chris Tidland after his best round of the week, a 68.