Boy Wonder didn't make it easy on himself on Labor Day at the TPC Boston. He tore up the turf on a tee shot that travelled 170 yards, and that was the only fairway he hit over the last five holes.
He had to make a 6-foot putt to save par from a bunker, and a 5-foot putt to save bogey after a pitch sailed from one side of the green to the other. And he had to wait as Louis Oosthuizen's birdie putt to force a playoff slid below the hole.
"I had a couple of wobbles coming in, but I obviously did enough and I'm very excited to get a victory," McIlroy said.
That's all anyone will remember.
On a leaderboard packed with some of the biggest names in golf — McIlroy, Oosthuizen, Tiger Woods, Phil Mickelson and Dustin Johnson — the 23-year-old from Northern Ireland took a giant leap toward establishing himself as the best in the game.
With four birdies in six holes at the start, and limiting the damage from his mistakes at the end, McIlroy closed with a 4-under 67 for a one-shot victory over Oosthuizen, joining Woods as the only three-time winners this year on the PGA Tour.
McIlroy goes to No. 1 in the FedEx Cup. And with one of his wins being the PGA Championship, that might be enough for his peers to vote him PGA Tour player of the year. He also has a comfortable gap in the world ranking, and could be tough to catch the rest of the year unless Woods were to win the next two FedEx Cup events.
"He's not No. 1 in the world for nothing," Oosthuizen said. "He's a great young talent, a lot of majors left for him to win. He's such a cool kid on the course. It's great playing with him. He makes tough shots look really easy sometimes, especially long irons.
"I don't think the back nine he hit the ball that great after what he did on the front nine, but he did what he had to do."
Woods made an early charge to get back in the hunt, though he never got closer than three shots until a two-putt birdie on the par-5 18th gave him a 66. He finished in third place, two shots behind, and earned enough money to become the first player to surpass $100 million in PGA Tour earnings.
Woods attributed that to higher purses, though he's responsible for those.
"I think we got some interest in the game of golf," Woods said. "A lot more youth, that's for sure."
One of those kids — McIlroy — keeps winning. The Honda Classic in March. The record eight-shot win in the PGA Championship. And now a FedEx Cup playoff event in Boston.
"Three is a great number," McIlroy said. "I'd like to make it four — or five — after the FedEx Cup."
Phil Mickelson also had a 66 and tied for fourth, along with Dustin Johnson, who had a 70 and likely played his way onto the Ryder Cup team. Brandt Snedeker made a strong case for a captain's pick with a 65-67 weekend to finish sixth.
Davis Love III will announce his four picks Tuesday morning in New York.
McIlroy had a three-shot lead with six holes to play, and only a clutch bogey putt on the 17th hole kept him from losing all of his lead.
Oosthuizen, who had to cope with pain in his right shoulder earlier in the round, came back with two birdies on the back to get within one shot. McIlroy hit a chip over the 17th green into more rough, and it looked as if he would struggle to make bogey.
Oosthuizen, however, missed the green from 140 yards in the fairway, chipped poorly to 10 feet and missed his par putt, and McIlroy calmly sank his 5-foot bogey putt to stay one shot ahead.
"The 17th hole cost me," Oosthuizen said.
McIlroy finished 20-under 264.
It was the second time this year that Oosthuizen, who won the British Open by seven shots at St. Andrews two years ago, failed to win after leading going into the final round. McIlroy made an early charge with three straight birdies, but the turning point came on the fifth hole when Oosthuizen felt pain in his shoulder on a tee shot that sailed into the trees and led to double bogey.
The pain went away on the back, which the South African attributed to an adrenaline rush.
McIlroy and Oosthuizen turned it into a two-man race, with Woods lurking until he couldn't convert enough putts. In the end, neither could Oosthuizen. He missed from just inside 10 feet for par on the 17th and from 12 feet on the 18th.
"I probably made all my putts yesterday," Oosthuizen said.
There was other drama at the Deutsche Bank Championship, though it was not nearly as compelling as the top of the leaderboard.
Charley Hoffman went from the first page of the leaderboard to an unimaginable collapse until he steadied himself at the end. Hoffman, who was 13 under after a birdie on the eighth hole, played his next nine holes in 8-over par, including a quadruple-bogey 7 on the par-3 11th. He came to the 18th needing a par to finish among the top 70 in the FedEx Cup and advance to the third playoff event next week in Indianapolis.
He went over the green in two, barely chipped onto the putting surface, and then ran his putt 12 feet by the hole. He made the putt for par, and moves on.
"I didn't expect to be playing next week," Hoffman said. "Shooting 42 on the back nine, I don't think I deserved to play next week. But I guess I've got another chance."
Others who advanced included Dicky Pride, who birdied his last two holes to get the 70th spot by one stroke over Jonas Blixt; and Chris Kirk, who stumbled at the start only to birdie four of his last five holes.
Oosthuizen had a three-shot lead at the start of the final round, though he was never expecting an easy time. McIlroy rallied to cut a six-shot deficit in half on the back nine of the third round to give himself a chance, another example why he is No. 1 in the world.
Sure enough, McIlroy came out firing with three straight birdies, starting with a two-putt from the fringe on the par-5 second.
The fifth hole changed everything.
Oosthuizen reached for his shoulder after a horrific snap hook off the tee. The ball dove into the woods and landed in the middle of shoulder-high bushes, leaving him no option but to take a penalty drop out of the hazard. He laid up short of the creek and two-putted for double bogey. They were tied, because McIlroy's tee shot found a clump of native grass on the edge of a bunker, and he had to chip out short of the creek and made bogey.
Oosthuizen, though, was clearly hurting. He couldn't get through his swing on the next tee shot, which sailed into the bunker and kept him from attacking the pin. That's what McIlroy did, hitting 9-iron into 3 feet for birdie and his first lead. He never gave it back.