LOUISVILLE, Ky. (AP) — Bobby Jones. Jack Nicklaus. Tiger Woods.

And, now, Rory McIlroy.

He certainly doesn’t look out of place.

Joining an exclusive club in the twilight at Valhalla Golf Club, McIlroy survived his toughest test yet on the big stage and gave every indication that he’s worthy of a spot alongside the greats of the game.

“I was happy being a two-time major champion coming into the year,” McIlroy said. “All of a sudden I’m a four-time major champion.”

That’s where those other three — Jones, Nicklaus, Woods — come in.

Until Sunday, they were the only players in the last century to win four majors at 25 or younger. McIlroy joined them with a victory that showed he’s not just the ultimate front-runner.

The kid can come from behind, too.

McIlroy went into the final round one shot ahead. By the time he stood in the 10th fairway, he was three strokes behind against an All-Star cast — Phil Mickelson, a five-time major champion; Rickie Fowler, runner-up at both the U.S. Open and the British Open; and Henrik Stenson, a perennial contender in the majors.

That’s when McIlroy unleashed a shot that he’ll surely be remembered for as long as he plays the game — a 3-wood from 284 yards on the par-5 hole. He insisted that when it left the club, it was about 30 feet lower than he wanted, and about 15 yards left of his intended target. But it worked out just the fine, the ball stopping 7 feet from the flag to set up an eagle that got him right back in the game.

“You need a little bit of luck in major championships to win,” he said, “and that was my lucky break.”

He took the outright lead when all three of his challengers eventually made bogey, and finally gave himself some breathing room with a 9-iron from a fairway bunker to 10 feet for birdie on the 17th.

McIlroy took a two-shot lead to the par-5 closing hole, where a two-putt in the gathering darkness was good enough for a 16-under 268 and a one-stroke victory over Mickelson. Stenson and Fowler finished two shots back.

“I thought winning the (British) Open championship a few weeks ago had sort of put me on a higher level in this game,” McIlroy said. “I never thought I’d get this far at 25 years of age.”

He’s not ready to stop now. The next two goals on his list are the career Grand Slam and capturing more major championships than any other modern European golfer.

Don’t bet against him.

“He’s better than everyone else right now,” Mickelson said. “He’s good, really good.”

McIlroy’s only missing major is the Masters, and he’s already counting down the days until next April. The Northern Irishman also has his eye on England’s Nick Faldo, whose six majors titles are more than any European golfer in the last century.

“I’ve got to take it one small step at a time,” McIlroy insisted. “Hopefully, when I achieve those, I can start to think about other things.”

McIlroy’s first two major titles, at the 2011 U.S. Open and the 2012 PGA Championship, where both eight-shot romps where he was never seriously challenged on the final day. At the British Open last month, he led by six shots going to Sunday and never surrendered the advantage.

This one was different, and not just because of the bizarre way it ended, with the final two groups essentially morphing into a foursome in a frantic bid to avoid a Monday morning finish.

A rain delay of nearly two hours pushed back the starting time for the final group — McIlroy and Bernd Wiesberger — to 4:19 p.m. The sun has dipped below the horizon by the time McIlroy finished up, barely able to see the contour of the greens but with enough light to get down in two from 35 feet for par.

Mickelson and Fowler, in the next-to-last group, hit their tee shots at the 18th hole, then stood aside for McIlroy and Wiesberger. After hitting their second shots, Mickelson and Fowler stood off to the side of the green while the last two guys hit again. Mickelson just missed chipping in for eagle and settled for a birdie, while Fowler missed a short putt and dropped him into a tie for third with Stenson.

McIlroy blasted out of a bunker and rolled his putt right up next to the hole for a clinching tap-in that capped a riveting display of golf, just what the game needed after three lackluster majors and Tiger Woods missing the cut at Valhalla.

“This was different than my previous major wins,” McIlroy said. “I showed a lot of guts to get this one done.”

For Fowler, it was another major disappointment.

He became the first player to finish in the top five of every major over the course of a year without actually winning one.

“This is the first one that hurts,” Fowler said. “Obviously, I did some great playing this year. My performance in the majors is something I can look back on and be proud of.”

No one does it better than McIlroy, who has become the game’s most compelling figure at a time when Woods — the winner of 14 majors but none since 2008 — seems at a crossroads because of age and injuries.

This definitely seemed like a changing of the guard, with McIlroy winning his second major of the summer while Woods didn’t even make it to the weekend.

“I’ve got that sense of belief in myself now,” McIlroy said. “I go into every tournament I play knowing I can win. It’s a great feeling to have.”