Triple major winner Padraig Harrington held off a last-day charge by US Open champion Webb Simpson to win the end-of-season PGA Grand Slam of Golf in Bermuda by one shot.
The Irishman, a late addition to the elite four-man field, fired a four-under-par 67 for a nine-under total of 133 in the 36-hole event.
Two strokes ahead of Masters champion Bubba Watson overnight, Harrington mixed five birdies with a lone bogey at the par-four last to fend off American Simpson, who closed with a best-of-the-week 65.
It was the 41-year-old Irishman's first victory since 2010, and a case of third time lucky for him at the Grand Slam of Golf.
Harrington had twice been beaten in playoffs at the event, losing to Argentina's Angel Cabrera in 2007 and being edged out by American Jim Furyk in 2008.
Left-hander Watson carded a roller-coaster 71 to finish a distant third at three under, level with fellow American and defending champion Keegan Bradley in the event which brings together the winners of the year's four majors.
Bradley, winner of last year's PGA Championship, gained his spot in the field as the first alternate after Northern Ireland's Rory McIlroy pulled out due to a scheduling conflict.