Rory McIlroy reaffirmed golf’s new world order with a stirring victory in the second US PGA Tour playoffs event in Boston, while Australians Adam Scott and John Senden made significant moves in the FedEx Cup.

Starting three shots back, world No.1 McIlroy held off fellow major champions Louis Oosthuizen and Tiger Woods with a closing four-under-par 67 at TPC Boston on Monday to triumph at 20-under 264.

It left the 23-year-old Northern Irishman one shot clear of South African Oosthuizen (71) and two ahead of former world No.1 Woods (66), claiming his fifth US tour win, and his third of 2012.

It was also McIlroy’s second victory in three starts, having won the US PGA Championship by a record eight shots last month, and took him past Woods to the top of the Fedex Cup points standings going into the last two playoff events.

“Today was great. I am delighted to get this win, delighted to go to No.1 in the FedEx Cup because it sets me up for a great next couple weeks,” McIlroy said.

“Going out with a three shot deficit I just wanted to and maybe put Louis under a little bit of pressure.

“I was able to do that playing the first four holes three-under. There were a couple of shots on the back nine I would’ve liked again but I still managed to do enough so I’m very pleased.”

Regardless of his finish at Crooked Stick in Indiana next week, the win guarantees McIlroy will enter the Tour Championship in Atlanta knowing a win there would also earn him the FedEx Cup title and its $US10 million ($A9.80 million) bonus prize.

Scott made a final round charge, carding a 66 to tie for seventh, eight shots behind McIlroy, while Senden was close behind in 12th spot giving the Australian pair a leg up into the third playoff event next week.

Scott moved to 25th in the FedEx Cup standings while Senden jumped to 26th.

The top 70 in the season-long points race advance to Crooked Stick later this week before the top 30 move on to the Tour Championship for a shot at not only a prestigious win, but also the FedEx Cup and its massive payday.

In the previous three seasons only an average three players have moved in or out of the top 30 in the penultimate week, meaning Scott and Senden are well placed to go all the way to Atlanta.

“I had the weekend I wanted,” Scott said.

“I salvaged something out of this week after a frustrating first two days.

“I felt like I played well enough to win yet I’m eight shots back because I just didn’t putt well.”

It was the first time all year the 32-year-old put together four rounds under par in a tournament.

“I am desperate for a win this year to be honest,” said Scott, whose ball striking has been superb.

“I have played a lot of good golf without a win so I’d really like to fix that.

“I putted better over the weekend which is positive going forward because I feel with my game this sharp I can certainly win next week’s tournament and then I’ve won in Atlanta before so anything’s possible.”

Greg Chalmers, Marc Leishman and Geoff Ogilvy also survived to play next week but Aaron Baddeley and Jason Day were bundled out.

“I’m more than a little disappointed,” Baddeley said.

“Little is a massive understatement. It was a learning year for me. I learnt a lot about the swing action but results-wise it’s a pretty average year.”

Despite the birth of his first child and back and ankle injuries during the year Day refused to give himself a pass for a lean season.

“I don’t want to make excuses,” he said. “I have no-one to blame except for myself.

“I will use the Fall Series events as the building blocks of improvement and see them as two opportunities to win.

“It’s how you come out of the tough years that is important.”