(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.
@highlight
Keegan Bradley wins PGA Grand Slam of Golf in Bermuda
@highlight
Rookie professional cards a level-par 71 for four-under 138
@highlight
Charl Schwartzel one-shot back after brilliant second round 65
@highlight
Bradley claimed PGA Championship in Atlanta to earn invite to prestigious event
"It was a lot more intense than I thought it was going to be," @placeholder told gathered reporters after his victory.