( CNN ) -- Keegan Bradley rounded off a triumphant rookie season by claiming the PGA Tour 's Grand Slam of Golf in Bermuda Wednesday . Bradley held off a charging Charl Schwartzel of South Africa to win the prestigious end-of-season title by a shot after carding a level-par 71 on the Port Royal Golf Course . It left the American on four-under 138 for the two-round tournament which brings together the season 's four major winners . Masters champion Schwartzel produced a best of the day six-under 65 but was ultimately undone by his first round three-over par 74 . U.S. Open champion Rory McIlroy started the day in the joint lead with Bradley after their first round 67s , but fell away in blustery conditions to card a four-over 75 to finish in third place on level-par 142 . McIlroy 's Northern Ireland compatriot Darren Clarke was way off the pace as the British Open winner closed out a second round of 74 for nine-over 151 . The 25-year-old Bradley , who turned professional in 2008 , has enjoyed a remarkable first season on the PGA Tour , claiming the Byron Nelson Classic before his triumph in the PGA Championship where he beat Jason Dufner in a playoff . Remarkably , it was his first appearance in a major , only one of three golfers to achieve the feat . He kept his nerve as Schwartzel drew level through the turn after picking up five straight birdies . Bradley , who had bogeyed the opening hole , birdied the 10th to open up a one-shot lead over Schwartzel which he kept to the finish to claim the $ 600,000 first prize . `` It was a lot more intense than I thought it was going to be , '' Bradley told gathered reporters after his victory . `` Coming down the stretch , it felt like any other tournament that I played in . It was very , very intense , and I was nervous over that 5-footer to win . ''
Keegan Bradley wins PGA Grand Slam of Golf in PGA Championship . Rookie professional cards a level-par 71 for four -under four . Keegan Bradley one-shot back after brilliant third round 65 . Bradley claimed Atlanta in Atlanta to earn invite to prestigious event .