Three weeks after winning the British Open, the 25-year-old from Northern Ireland took his second major victory in a row and third consecutive triumph overall in impressive fashion yesterday.
McIlroy fired a three-under par 68 in the final round to finish 72 holes on 16-under par 268 and edge five-time major winner Phil Mickelson by one shot with Sweden’s fourth-ranked Henrik Stenson and British and US Open runner-up Rickie Fowler two adrift.
The 25-year-old from Northern Ireland took the Wanamaker Trophy, even grabbing the lid as it fell during the awards ceremony, and a $1.34 million (7.45 million euro) top prize.
McIlroy’s hat-trick of victories after the British Open and a World Golf Championships event last week give him the longest win streak since Tiger Woods completed a run of five in a row in 2008.
McIlroy became the fourth-youngest man to win his fourth major, trailing only Young Tom Morris, Tiger Woods and Jack Nicklaus, and has taken four of the past 15 majors contested.
Four of golf’s biggest stars staged a trophy battle down the backstretch worthy of anything the Kentucky Derby horses at nearby Churchill Downs ever produced.
Drenched by 2.2 inches of rain in three days, Valhalla offered birdie chances while the back nine turned up the tension and produced a spectacle.
Adding to the pressure was a rain delay of nearly two hours that left the leaders racing to finish before nightfall, dark clouds looming over the 18th green as McIlroy finished in twilight.
McIlroy opened the back nine with an eagle, added a birdie on 13 and sank a tense 10-foot birdie putt at the 17th hole to seize a two-stroke advantage.
McIlroy found the right rough off the tee at the par-5 18th and a greenside bunker with his approach while Mickelson and Fowler were on the green. Mickelson missed an 70-foot eagle bid but tapped in for birdie to pull within one of McIlroy while Fowler settled for par to end his title hopes.
McIlroy blasted out to 34 feet, left a birdie putt inches shy of the cup and parred to seal the most hard-fought of his major wins.
McIlroy is the first man to win two majors in a row or in the same year since Ireland’s Padraig Harrington took the British Open and PGA in 2008.
McIlroy joined Harrington, Woods, Walter Hagen and Nick Price as the only men to win the British Open and PGA in the same season.
McIlroy won the 2011 US Open, 2012 PGA Championship and last month’s British Open at Hoylake by keeping big leads through the final round, but had to charge from behind on the back nine yesterday.
US left-hander Mickelson shared the lead with McIlroy at 15-under but found the rough at 16, bounced his bunker shot over the hole and left a 10-foot par putt just short.
The resulting bogey dropped Mickelson to 14-under with Fowler, who rescued par at 16 after hitting his tee shot into a muddy spectator area at the adjacent 15th hole, and Stenson.
Mickelson and Fowler parred the 17th while McIlroy sent his tee shot on the hole into a right-side fairway bunker.
But McIlroy responded with a clutch blast that landed 10 feet from the cup for a birdie chance and curled the putt home, a clenched right fist his only sign of enjoyment at a two-stroke lead.
Mickelson, Fowler and Stenson reached the turn level at 14-under, McIlroy having stumbled wtih two bogeys in the first six holes while Stenson fired five birdies and the Americans had four each.
Fowler holed a 28-foot birdie putt at the par-5 10th to reclaim the lead alone at 15-under.
McIlroy smashed his approach 274 yards to seven feet at the par-5 10th and sank the eagle putt to reach 14-under.
Mickelson followed with a 10-foot birdie at 11 to 15-under, matching Fowler for the lead.
Stenson answered with a birdie at 13, putting his approach two feet from the cup, to reach 15-under, but lipped out on a three-foot par putt at the par-3 14th to fall back, leaving the Americans at 15-under and the Europeans on 14-under.
McIlroy grabbed a share of the lead with a five-foot birdie putt at the 13th, a passionate right fist punch signaling his excitement.
Fowler buried his tee shot in mud at 14 and missed a 17-foot par putt, a bogey dropping him to 14-under, leaving McIlroy and Mickelson sharing the lead. Despite the defeat, Fowler became only the third player to finish in the top five at all four majors in a single year.