Indianapolis - Rory McIlroy fired a five-under par 67 on Sunday to win the BMW Championship, holding off an elite field to win a second straight title in the US PGA Tour's playoff series.
McIlroy, who won the Deutsche Bank Championship last week by one stroke, finished with a 20-under par total of 268, two shots in front of Phil Mickelson and Lee Westwood.
After claiming the second major title of his career at the PGA Championship last month, the world number one nabbed his fourth US tour title of the season and the sixth of his career.
England's Westwood carded a 3-under 69 at Crooked Stick, while Mickelson posted a 70 for 270.
McIlroy had six birdies on the day, breaking out of a four-way tie for the lead with birdies at nine and 10. Two more birdies at 15 and 16 gave him enough of a cushion to make his bogey at 18 irrelevant.
"I felt like I was a little bit more on my game last week, I scrambled really well yesterday to still give myself a chance going into today, and I did some great work on the range last night, and drove the ball beautifully today(Sunday)," McIlroy said. "I set myself up to attack these pins."
McIlroy became the first player since Tiger Woods in 2009 to win in successive weeks on the US tour and he joined Woods and Jack Nicklaus as the only players to win at least six PGA Tour events before his 24th birthday.
"I knew if I played to my ability that I would win events. I didn't think that everything would happen so quickly, but I'm just on a great run at the minute and trying to keep that going for as long as possible," McIlroy said.
McIlroy hit all but one fairway in the final round, taking advantage of the rain-softened course to attack the pins.
"He's going out there and is up near the lead and posts a good number," Woods said. "He's doing the things he needs to do, and as he said yesterday, he's feeling very confident about his game. Right now, he's just really played well, and he's making a ton of putts. That's a great combo."
Woods, never a serious threat to the lead, finished three off the pace after a 68 for 271. He was tied for fourth with Robert Garrigus (69).
Mickelson, who shared the overnight lead, was one stroke off the pace before a bogey at 12. Two late birdies pulled him within two, but he missed a three-footer (just under a meter) for par at 17 to fall back again.
"A lot of people stayed neutral and Rory geared ahead," Mickelson said.
The top 30 players in the playoff standings now advance to the finale, the Tour Championships at Eastlake in Atlanta in two weeks, where a $10 million bonus is on offer to the playoff series winner.
Defending FedEx Cup playoff champion Bill Haas was among those who didn't make it after a round that included a double-bogey and seven bogeys.
Also missing out on the Tour Championship was Fiji's Vijay Singh. The 49-year-old started the day tied for the lead but had three bogeys in a four-hole span on the back nine to see his hopes of winning -- and securing a Tour Championship berth -- evaporate.
Leading final-round scores on Sunday from the $8 million BMW Championship (USA unless noted, par-72):
268 - Rory McIlroy (NIR) 64-68-69-67
270 - Phil Mickelson 69-67-64-70, Lee Westwood (ENG) 68-65-68-69
271 - Robert Garrigus 67-69-66-69, Tiger Woods 65-67-71-68
272 - Dustin Johnson 68-67-67-70, Adam Scott (AUS) 68-68-66-70
273 - Vijay Singh (FIJ) 65-66-69-73
274 - Jim Furyk 69-70-67-68
275 - Ryan Moore 66-66-73-70, Bo Van Pelt 64-69-71-71
276 - Zach Johnson 67-69-68-72, Chris Kirk 68-68-69-71, Ian Poulter (ENG) 68-68-69-71, Bubba Watson 69-71-71-65
- Greg Chalmers (AUS) 74-70-68-66, Tom Gillis 69-67-73-69, Padraig
Harrington (IRL) 70-65-70-73, John Huh 70-66-73-69, Troy Matteson
70-66-71-71, Seung-Yul Noh (KOR) 68-66-73-71, Louis Oosthuizen (RSA)
68-69-68-73, Justin Rose (ENG) 67-70-70-71
279 - Ben Curtis 70-69-68-72, Sergio Garcia (ESP) 69-69-71-70
280 - Kevin Na 72-71-68-69, Steve Stricker 68-73-68-71
- Luke Donald (ENG) 66-72-72-71, Jason Dufner 72-67-73-69, Ernie Els
(RSA) 68-71-69-73, Geoff Ogilvy (AUS) 68-71-74-68, Charl Schwartzel
(RSA) 69-68-72-72, Brendon de Jonge (ZIM) 71-66-71-73