Bridgestone: Justin Thomas turned on the jets midway through the third round and opened a three-stroke lead at the WGC-Bridgestone Invitational in Akron, Ohio, Saturday.
A week before defending his title at the PGA Championship, Thomas carded three-under 67 after starting the day tied for the lead with Englishmen Ian Poulter and Tommy Fleetwood.
The American gathered five birdies in nine holes from the sixth en route to a 14-under 196 total with one round left at Firestone Country Club.
Northern Irishman Rory McIlroy also had a 67 to jump into second place with Poulter (70) at 11-under. Tiger Woods plunged 11 shots behind after a poor 73.
Thomas and McIlroy are paired for the final round, potentially setting up a duel between the south Florida neighbours.
Australian Jason Day (69) moved into fourth place, four shots behind. Nobody has come from further back in the final round to win the championship.
World No.3 Thomas has won eight times on the PGA Tour, but is still after his first World Golf Championships title. He lost to Phil Mickelson in a playoff at the WGC-Mexico Championship in March.
McIlroy was satisfied with a bogey-free round, particularly the quality of his driving, as he smashed his tee shots more than 300 yards with monotonous regularity.
As McIlroy crept up the leaderboard, Fleetwood regressed. He got an unlucky break at the first hole when his approach shot hit the flagstick and clattered off the green, which set the tone for a 74 that left him seven shots back.
Woods, an eight-times champion at Firestone, dismissed speculation that his surgically-repaired back had bothered him.