Australia's Adam Scott, hungry for his first victory this year after several close calls, charged into an early three-shot lead at the WGC-Bridgestone Invitational on Thursday.
The world number six rattled up nine birdies and two bogeys on his way to a sparkling seven-under-par 63 in the opening round at Firestone Country Club.
American Lucas Glover was alone in second place after a 66 with compatriots Davis Love III and David Toms, Briton Luke Donald and New Zealander Michael Campbell, last year's US Open champion, a further stroke behind in third.
World number one Tiger Woods, bidding for his fourth successive PGA Tour title after winning the PGA Championship at Medinah on Sunday, was one under for the day after 15 holes.
Irishmen Padraig Harrington and Paul McGinley did not enjoy a good day out, finishing up at three-over and seven-over-par respectively.
