Akron, Ohio, Aug 2, 2012 (AFP) - Furyk fired a seven-under-par 63 to put him three ahead of a group of six players on four-under, including US Masters champion Bubba Watson and the world number one from England, Luke Donald, tied for second here last year.
Slattery took advantage of warm, windless conditions at the Firestone Country Club course to record four consecutive birdies beginning at the par-four No. 1 on his way to carding a five-under 65, just two behind.
English compatriot Simon Dyson was also in the group that shot 66, along with Aussie John Senden, American Ben Crane, and Rafael Cabrera Bello from Spain.
Starting from the 10th tee, Furyk rolled in an eight-foot birdie putt at the tenth hole and followed it up with a short birdie putt at No. 11.
"I gave myself a lot of good opportunities, good angles into pins, hit some crisp, good iron shots, hit some close where I had three or four very short birdie putts, and it was nice to see some putts go in today and knocked in some birdie putts," said Furyk.
Seven-time tournament champ Tiger Woods three-putted from 25 feet on the par-five 18 to finish with an even-par 70. The world number two made bogey on three holes on the back nine.
"I hit the ball well I just putted atrociously," Woods said. "I didn't hit any putts hard enough and that's what is frustrating.
"I was making it a little too complicated out there. I have done this a long time. I was trying to keep plugging away unfortunately it went the wrong way."
Defending champion Adam Scott of Australia shot a one-over 71 in his first competition since he bogeyed the last four holes two weeks ago to lose the British Open to South African veteran Ernie Els.
Els had a three-over 73 in the first round at Firestone.
PGA Champion Keegan Bradley, Sergio Garcia, Jason Dufner, Louis Oosthuizen, Geoff Ogilvy, Retief Goosen, Carl Pettersson, K.T. Kim and Bill Haas were tied in ninth at three-under 67.
Phil Mickelson shot a one-over 71, while Northern Ireland's Rory McIlroy had an even-par 70.
Leading first-round scores on Thursday in the $8.5 million WGC-Bridgestone Invitational (USA unless noted, par-70):
63 - Jim Furyk
65 - Lee Slattery (ENG)
66 - Rafael Cabrera-Bello (ESP), Ben Crane, Luke Donald (ENG), Simon Dyson (ENG), John Senden (AUS), Bubba Watson
67 - Keegan Bradley, Jason Dufner, Sergio Garcia (ESP), Retief Goosen (RSA), Bill Haas, K.T. Kim (KOR), Geoff Ogilvy (AUS), Louis Oosthuizen (RSA), Carl Pettersson (SWE)
68 - Jamie Donaldson (WAL), Zach Johnson, Martin Kaymer (GER), Martin Laird (SCO), Steve Stricker, David Toms, Lee Westwood (ENG)
69 - Dustin Johnson, Scott Piercy, Charl Schwartzel (RSA), Kyle Stanley, Nick Watney, Y.E. Yang (KOR)