Keegan Bradley only needed an even-par 71 on Wednesday to win the PGA Grand Slam of Golf by a single stroke at Port Royal Golf Course.
Bradley finished at four-under 138 for the victory at the championship with the most elite field in golf.
This two-day tournament was reserved for the four major winners of 2011.
Bradley, the PGA Champion, defeated Masters winner Charl Schwartzel by a shot after the South African fired a six-under 65 on Wednesday.
U.S. Open champion Rory McIlroy shared the first-round lead with Bradley, but a four-over 75 in the final round dropped the Northern Irishman to third place at even-par 142.
Open Champion Darren Clarke finished a distant fourth after a three-over 74 on Wednesday left him at plus-nine.
Bradley struggled early with bogeys at one, five and six. He atoned for the error with a birdie at the par-five seventh, but, despite the front-nine woes, he still found himself tied for the lead.