Rory McIlroy needed three weeks to catch his breath after his first major victory, and it took him until the end of last year before he was back in the form that would eventually make him the No. 1 golfer in the world.

The hangover was much shorter after he picked up his second major last month.

In his second tournament since winning at the PGA Championship at Kiawah Island by eight strokes, McIlroy shot a final-round 67 to win the Deutsche Bank Championship on Monday. McIlroy finished at 20-under-par, one stroke ahead of Luis Oosthuizen and two in front of Tiger Woods, to earn his third victory of the year, move to the top of the FedEx Cup standings and establish himself as the favorite for the PGA's player of the year.

"He's not No. 1 in the world for nothing," said Oosthuizen, who led by three strokes heading into the day but fell to second with a double bogey on No. 5. "He's a great young talent, (with) 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."

McIlroy won the U.S. Open last year for his first victory in a major and then took some time off for the commitments — and celebration — that followed. He struggled when he returned, including a 25th at the British Open and a 64th at the PGA Championship, before righting himself in the fall with a slew of top-five finishes.

"I had a lot going on at that time, and probably didn't handle it the best," McIlroy said after claiming a check for $1.44 million. "I've learned how to handle winning big events and carrying myself forward and not dwelling on what's happened."

McIlroy won the PGA Championship on Aug. 12, becoming the youngest player to win two majors since Seve Ballesteros. He finished tied for 24th last weekend at The Barclays and hovered near the top of the leaderboard all Labor Day weekend with a pair of 65s in the first two rounds followed by a pair of 67s to join Woods as the only three-time winners on the PGA Tour this year .

"There's a time and a place to celebrate and to enjoy what you've done, and going into the playoffs isn't it," said McIlroy, who also won the Honda Classic in March. "This run that we're on, we just have to keep thinking about the next week, and once Ryder Cup is over, for sure I'll think back and I'll celebrate and I'll enjoy the great golf that I've played over the last few weeks."

Woods, who won here in 2006, never got closer than three shots until a two-putt birdie on the par-5 18th gave him a 66 — good for third place and a check for $544,000 that made him the first $100 million man on the PGA Tour. Woods has earned $100,350,700; next on the list is Phil Mickelson — more than $30 million behind at $66,805,498 after finishing fourth at the Deutsche Bank.

"The purse increase helps," Woods said. "I won fewer tournaments than Sam Snead has, but obviously he was in a different era. It's just that we happened to time it up right and happened to play well when the purses really had a nice spike up."

Mickelson shot 66 on Sunday to tie for fourth 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, but needed a bogey putt on the 17th to stay in front after Oosthuizen, despite pain in his right shoulder, came back with two birdies to get within one.

McIlroy hit a chip shot over the 17th green into more rough, but Oosthuizen missed the green from 140 yards in the fairway, chipped poorly to 10 feet and missed his par putt. McIlroy calmly sank his 5-foot bogey putt to stay one shot ahead.

"I had a couple of wobbles coming in," McIlroy said. "But I obviously did enough and I'm very excited to get a victory."

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 convert a third-round lead into a victory.

McIlroy quickly cut into the three-stroke lead with three straight birdies, but Oosthuizen also birdied the fourth hole to move to minus-20.

Then came No. 5.

Oosthuizen hit a snap hook off the tee that left him reaching for his right shoulder as the ball dove into the woods and landed in the middle of shoulder-high bushes. He had no option but to take a penalty drop out of the hazard, then laid up short of the creek and two-putted for double bogey.

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 to make bogey.

They were tied.

But Oosthuizen was hurting. He couldn't get through his swing on the next tee shot, which sailed into the bunker. He said adrenaline helped him forget about the pain.

But it was too late.

McIlroy went right at the sixth flag, hitting 9-iron into 3 feet for birdie and a lead that he never gave back.

"It was a great bonus after making bogey at the fifth to bounce straight back with that birdie," McIlroy said. "Once I got into the lead, I felt very comfortable. ... It worked for the most part. Obviously had a couple wobbles there coming in, but did enough in the early part of the round to have enough of a cushion to get the job done."

Woods lurked until the end — he had a 23-foot eagle putt on 18 that would have put him within a stroke of the leaders — but it was really a two-man race until Oosthuizen 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.

The drama wasn't only at the top of the leaderboard, though: Charlie Hoffman was trying to salvage a spot in the top 70 in the FedEx Cup standings to advance to the third playoff event next week in Indianapolis.

Hoffman, who won here two years ago, was 13 under after a birdie on the eighth hole before playing his next nine in 8-over par — including a quadruple-bogey 7 on the par-3 11th. He came to the 18th needing a par to advance.

Hoffman went over the green in two, barely chipped on and then ran his putt 12 feet past the hole.

He made the putt for par.

"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.