PGA golfer Rory McIlroy hits from the 12th fairway during the final round of the 2014 PGA Championship golf tournament at Valhalla Golf Club in Louisville, Kentucky, Aug 10, 2014. [Photo/Agencies]

Fowler became the first player in history to finish in the top five at all four majors without winning one. He closed with a 68 and tied for third with Henrik Stenson, who fell out of a share of the lead by missing a 3-foot par putt on the 14th hole. Stenson shot a 66.

McIlroy hit his second shot into a bunker, and he had to two-putt from 35 feet for the win. He lagged the first one to tap-in range, and the major was his. McIlroy repeatedly pumped his fist before letting out a scream above the gallery that had been treated to one of the best shows ever in a major.

He won his first two majors by eight shots at the 2011 US Open and 2012 PGA Championship. Only a month ago, McIlroy took a six-shot lead into the final round of the British Open and completed a wire-to-wire win with only a brief scare.

This was his first big test, and it took some of his best golf to come through.

"I think I showed a lot of guts out there to get the job done," he said.

The winning shot turned out to be that 9-iron from the bunker and the birdie putt on the 17th hole that gave him a two-shot lead, the largest margin for anyone on a day when as many as five players claimed a share of the lead.

It might not have been possible without a 3-wood on the par-5 10th hole.

Standing in the fairway, McIlroy watched Fowler drain a 30-foot birdie putt to take the outright lead. McIlroy was 281 yards away, slightly uphill, and his short caught the left side of the fairway and rolled onto the green before stopping 7 feet away for an eagle that got him back in the game.

Mickelson holed a 10-foot birdie putt on the 11th hole to tie Fowler, and it looked to be his day when he rolled in a 30-foot par putt on the 12th. Stenson hit a bold shot to the island-green 13th for a short birdie to tie for the lead, only to fall back.

McIlroy caught the leaders with a birdie on the 13th.

None of the other contenders made another birdie the rest of the way until it was too late.

All that was left after an exhausting day of raw emotions was the coronation. Not since Woods in 2008 has anyone won three straight tournaments, and they were big ones for McIlroy _ the British Open, a World Golf Championship and the PGA Championship. He played them in a combined 48-under par.

"He's better than everyone else right now," Mickelson said.