Rory McIlroy has won the PGA Championship by a record eight strokes after carding a six-under 66 at Kiawah Island, as Australia's Adam Scott failed to stay with the Northern Irishman in the final round.
Having taken control in the re-scheduled second half of his third round earlier on Sunday, McIlroy extended his lead over the final round to finish on 13 under for the tournament and take the world number one ranking.
The 23-year-old Northern Irishman finished well clear of England's David Lynn, who claimed outright second at five under.
Sunday's victory was McIlroy's second triumph at one of golf's majors, after he won the 2011 US Open, ironically also by eight shots.
He has passed that milestone at a younger age than Tiger Woods.
Carl Pettersson, Bo Van Pelt, Trevor Immelmann and Scott started the fourth round within four shots of McIlroy.
But all four could not match McIlroy on their final time around the Ocean Course on Kiawah Island.
Scott was one under after the first nine holes but a double-bogey on the 13th followed by a bogey on the 14th left the Australian out of contention at two under overall alongside five others.
The 32-year-old was tied for 11th with compatriot Geoff Ogilvy who carded a two-under 70 on Sunday, including an eagle on the second hole.
McIlroy did not drop a shot in his final round, birdying the second, third, seventh, 12th, 16th and 18th holes on his way to victory.
It was the first time a player had carded a bogey-free final round to win a major since Phil Mickelson at the Masters in 2007.
As McIlroy's main rivals at the start of the final round faltered, Lynn made a charge up the leaderboard but never challenged the man at the top.
Lynn scored five birdies and a bogey to finish the PGA Championship with a 68.
Carl Pettersson, who had been outright second after the third round, shot even par to finish in a group of four players tied for third, one stroke behind Lynn.
Pettersson was joined by England's Justin Rose and Ian Poulter, as well as reigning champion Keegan Bradley of the USA at four under.
Poulter drew within three shots of McIlroy when he shot five straight birdies to begin his final round.
But the 36-year-old Englishman faltered with three consecutive bogeys starting on the 13th hole and eventually carded a three-under 69.
Tiger Woods finished the tournament on two under in Scott and Ogilvy's group.
Woods had moved up to four under halfway through his final round but bogeys on the 11th and 16th ended any hope he had of a charge up the leaderboard.