Indianapolis - Rory McIlroy, who is fresh off a win last week at the Deutsche Bank Championship, fired an eight-under 64 Thursday to grab a share of the lead after the first round of the PGA Tour's BMW Championship.
Also in the hunt atop a crowded leaderboard is McIlroy's playing partner Tiger Woods, who is one stroke back after shooting a seven-under 65.
The 23-year-old Northern Irishman McIlroy birdied his last two holes to put him into a four-way tie for the lead at the Crooked Stick golf course.
Woods also made it look like just another day at the office, chipping in from 30 feet for birdie on his last hole.
"You know, with the soft conditions you could really shoot a number out there, and I did," said PGA Champion McIlroy.
"I took advantage of hitting the ball really well, hitting it in the fairway, which I need to do, and also hitting it long, and gave myself a lot of opportunities.
"I missed a few, but was able to make the most of them. Great start to the tournament."
Canada's Graham DeLaet, American Bo Van Pelt and US Open champ Webb Simpson also shot eight-under 64.
American Woods is tied for fifth with Fijian Vijay Singh.
Luke Donald, Ryan Palmer and Ryan Moore share seventh place at minus-six.
The players were playing under lift-clean-and-place rules due to a wet course softened up by the heavy rains over the past week.
McIlroy posted back-to-back 67s on Sunday and Monday to win the Deutsche Bank Championship. That helped him increase his lead atop the world rankings and gave him momentum entering this tournament.
McIlroy began his round with a birdie on the 10th hole and then had an eagle on 15 and birdie at 18 to make the turn at three under.
He birdied the eighth to get within one of the lead and then rolled in another birdie putt on the par-five ninth.
Woods started quickly with birdies on three of his first four holes. He chipped in for a birdie on the ninth to finish one shot adrift of McIlroy and the other leaders.
"I was scoring," Woods said. "I wasn't playing particularly well, but I scored. Rory on the other hand played beautifully today.
"Every single part of his game was working. It all looked good. I was very fortunate to post the number I shot."
Starting on the back nine, DeLaet posted three birdies in a row from the 11th. He finished in style with an eagle on the ninth to vault up the crowded leaderboard.
Leading first-round scores here on Thursday from the $8 million BMW Championship (USA unless noted, par-72):
64 - Graham DeLaet (CAN), Rory McIlroy (NIR), Webb Simpson, Bo Van Pelt
65 - Vijay Singh (FIJ), Tiger Woods
66 - Luke Donald (ENG), Ryan Moore, Ryan Palmer
67 - Ben Crane, Rickie Fowler, Robert Garrigus, Zach Johnson, Justin Rose (ENG), Jimmy Walker
- Ernie Els (RSA), Matt Every, Dustin Johnson, Chris Kirk, Graeme
McDowell (NIR), Seung-yul Noh (KOR), Geoff Ogilvy (AUS), Louis
Oosthuizen (RSA), Ian Poulter (ENG), Adam Scott (AUS), Kyle Stanley,
Steve Stricker, Lee Westwood (ENG)