Michael Thompson has held off a late surge from Geoff Ogilvy with a birdie on the 18th hole to win the Honda Classic by two shots.
The 27-year-old American carded a one-under 69 to finish on nine under for the tournament, two strokes clear of Australia's Ogilvy, who birdied two of the last three holes to keep the pressure on Thompson.
Thompson started Sunday's fourth round tied for the lead with Luke Guthrie, who dropped back with a bogey on the second hole at the PGA National Champion Course in Florida.
In an inconsistent front-nine performance, Thompson eagled the par-five third hole before producing three bogeys and two birdies to be one under for the round heading to the 10th.
A string of six pars steadied the ship for Thompson at the start of the back nine.
While Ogilvy moved within one shot of the top of the leaderboard when Thompson bogeyed the 16th, the Australian missed a long eagle putt on the 18th, which would have given him a share of the lead.
Thompson birdied the last hole to wrap up his first PGA Tour victory.
Ogilvy started the day two shots off the lead but could not take advantage of Thompson and Guthrie's inconsistent starts to the fourth round, holing 13 straight pars before he bogeyed the 14th.
A birdie on the 16th gave Ogilvy a sniff of victory but his long-range putt for eagle on the 18th was just off line and the 35-year-old Australian had to settle for second place.
Guthrie had a terrible final day at Palm Beach with four bogeys and a double bogey, carding a three-over 73 to finish on five under for the tournament, two strokes adrift of Ogilvy.
Americans Keegan Bradley, Erik Compton and Lucas Glover and Englishmen Justin Rose and David Lynn were a further two shots back in a tie for fourth.
England's Lee Westwood, South African Charl Schwartzel, Northern Irishman Graeme McDowell and Canadian Graham DeLaet were next on the leaderboard – all on two under in a share of ninth.
Matt Jones was the next best Australian, finishing on even par for the tournament after a two-under 68 on Sunday, while Steven Bowditch (three over), Greg Chalmers (seven over), Marc Leishman (eight over) and Cameron Percy (12 over) were all well off the pace after making the cut.