Los Angeles - Justin Thomas had six birdies in a three-under par 67 on Saturday to seize a three-shot third-round lead at the WGC Bridgestone Invitational, where Tiger Woods faded from contention.
Thomas, who defends his PGA Championship title next week at the last major of the year, is rounding into form just at the right time.
A two-time winner early this season, has finished inside the top 10 just once in his last eight starts.
One over through the first five holes after a birdie and two bogeys, he produced five birdies in a nine-hole span to separate himself from a star-studded chasing pack.
"I just need to continue to go out and play well tomorrow because I have a lot of really good players chasing me," said Thomas, who will play in the final group on Sunday with Northern Ireland star Rory McIlroy.
McIlroy carded a three-under 67 to share second on 199 with overnight co-leader Ian Poulter of England, who carded a 70.
Former world No 1 Jason Day was alone on 200 after a 69.
Woods, an eight-time winner at Firestone Country Club, which is hosting the Bridgestone for the last time, couldn't keep pace.
He started the day five off the lead and carded a three-over 73 that left him 11 adrift.
"I'm fine. I just played like crap," Woods said. "I didn't warm up very well, I didn't hit the ball crisp or clean. Very similar to, you know, (to) the first day. The difference is, I made everything the first day.
"Today, I didn't make anything."
With the Firestone Country Club greens firming up in warm, sunny weather, all of the contenders predicted a tough challenge on Sunday.
"The hard part about this course is you can get off track pretty quick if you're not playing well," Thomas said. "I think that's why with it being softer this week you're seeing a big variety of scores, because it's soft enough where if you're playing well you can shoot low but if you're not you can shoot some pretty high numbers."
McIlroy was pleased with a round in which he hit nine of 14 fairways, producing three birdies without a bogey.
"I like to hit driver as much as possible and this course allows me to do that," McIlroy said.
"It allows you to be aggressive off the tee. Nine out of 14 fairways for me today is a really good number. If I can do that tomorrow hopefully I'll have a chance."
Leading third-round scores on Saturday in the World Golf Championships Bridgestone Invitational at Akron, Ohio (USA unless noted, par 70):
196 - Justin Thomas 65-64-67
199 - Rory McIlroy (NIR) 65-67-67, Ian Poulter (ENG) 62-67-67-70
200 - Jason Day (AUS) 65-66-69
201 - Marc Leishman (AUS) 65-69-67, Kyle Stanley 63-68-70
202 - Rickie Fowler 63-74-65, Jon Rahm (ESP) 64-70-68
203 - Louis Oosthuizen (RSA) 68-66-69, Tommy Fleetwood (ENG) 66-63-74
204 - Patrick Cantlay 64-72-68, Brooks Koepka 66-70-68, Rafa Cabrera Bello (ESP) 68-67-69, Anirban Lahiri (IND) 65-70-69, Luke List 65-68-71, Kim Si-woo (KOR) 64-68-72
205 - Aaron Wise 67-71-67, Matt Kuchar 68-70-67, Webb Simpson 69-65-71, Tony Finau 68-66-71, Li Haotong (CHN) 66-67-72
206 - Dustin Johnson 69-71-66, Sergio Garcia (ESP) 70-69-67, Zach Johnson 69-70-67, Thorbjørn Olesen (DEN) 71-67-68, Patrick Reed 66-70-70, Ross Fisher (ENG) 67-68-71
207 - Bubba Watson 71-69-67, Gary Woodland 67-71-69, Kevin Na 65-72-70, Phil Mickelson 66-69-72, Tyrrell Hatton (ENG) 68-67-72, Tiger Woods 66-68-73