Miami - Henrik Stenson clung to a one-stroke lead after Saturday's third round of the PGA Arnold Palmer Invitational while Tiger Woods, Rory McIlroy and Justin Rose surged into the title hunt.
Sweden's Stenson, the 2016 British Open champion, fired a one-under par 71 to stand on 12-under 204 after 54 holes at Bay Hill as American Bryson DeChambeau shot 72 to stand one stroke adrift.
But the 36-hole leaders couldn't expand their edge, allowing Rose, McIlroy and Woods among others to charge into a Sunday showdown, 12 rivals in all within five strokes of Stenson at the Orlando layout.
"I could have a two- or three-shot lead, which would have been a nice cushion, but I've been in the mix a few times and I'm back here trying to give it a go," Stenson said.
Four-time major champion McIlroy, who needs only a Masters green jacket to complete a career Grand Slam, birdied two of the last three holes to fire 67.
It was the Northern Irishman's best US PGA round since the first round last August at Akron and he stood third on 206 a week after missing the cut.
"Worked on my swing a little bit, found a feeling, found something I could go with for this week and maybe beyond," McIlroy said.
"Freed up my putting a little bit. Felt a little bit more in control of my game. I knew if that could translate from practice onto the course, I could have a good week."
England's Rose made six birdies against a lone stumble, a three-putt bogey at 15, to shoot 67 and share fourth on 207 with American Ryan Moore.
South Korea's An Byeong-hun was in a pack on 208 that also included Americans Rickie Fowler, Talor Gooch and Charley Hoffman.
And then came Woods, who birdied two of the last three holes for a 69 to share 10th on 209 with US compatriots Patrick Reed, Bud Cauley and Grayson Murray.
"I figure I'm within reach if I shoot a really, really low round tomorrow," Woods said. "I'm going to have to shoot a low one and get a little bit of help. But my responsibility is to go out and shoot a low one first."
Stenson had four consecutive top-10 showings between 2013 and 2016 but has yet to win at Bay Hill.
Stenson opened with a 13-foot birdie putt and answered a bogey at eight with a 30-foot birdie putt at nine. He answered a bogey at 10 with birdies at the par-5 12th and 16th, only to miss the green at the par-3 17th on the way to bogey.
"Especially with the way I played coming in, I think that I didn't really miss a shot the last six holes," Stenson said.
McIlroy blasted out of a bunker to two feet to birdie the par-5 fourth and sank a 12-foot birdie putt at nine.
After bogeying 11, McIlroy landed his approach at 12 eight feet from the cup and sank the eagle putt, then used great approaches at 16 and 18 to set up tap-in birdies.
Woods, a 14-time major winner making a comeback after back surgery, showed solid form at the Bay Hill course where he has captured eight career titles.
With the Masters only three weeks off, Woods now has nine consecutive rounds of par or better -- his longest such US PGA streak in more than five years.
Woods curled in a 12-foot birdie putt at the par-4 18th to complete his day, cocking for a full-speed fist pump before adopting a mellow low-key finish.
Woods found a greenside bunker and made bogey at the par-3 second, but birdied three of the next four holes, his longest putt a curvy 38-footer at the third.
After missing a 10-footer for par at the eighth and making a 10-footer to birdie 11, Woods went birdie-bogey at 16 and 17 after finding bunkers at each, then made his closing birdie.
"Never give in to the golf course (or) certain shots," Woods said. "(I'm) just trying to make the best possible score and dig it out on every hole."
Leading scores after Saturday's third round of the US PGA Tour Arnold Palmer Invitational at Bay Hill (USA unless noted, par 72):
204 - Henrik Stenson (SWE) 64-69-71
205 - Bryson DeChambeau 67-66-72
206 - Rory McIlroy (NIR) 69-70-67
207 - Justin Rose (ENG) 69-71-67, Ryan Moore 71-67-69
208 - Charley Hoffman 71-66-71, Rickie Fowler 67-71-70, Talor Gooch 65-70-73, An Byeong-hun (KOR) 68-68-72
209 - Grayson Murray 71-69-69, Tiger Woods 68-72-69, Bud Cauley 72-67-70, Patrick Reed 68-70-71
210 - Ollie Schniederjans 71-71-68, Graeme McDowell (NIR) 69-72-69, Chris Kirk 71-69-70, Sam Burns 69-70-71
211 - John Huh 72-73-66, Austin Cook 72-73-66, Jason Day (AUS) 73-71-67, Patrick Rodgers 72-71-68, Brian Stuard 74-69-68, Sam Horsfield (ENG) 70-73-68, William McGirt 70-71-70, Jamie Lovemark 73-68-70, Zach Johnson 69-71-71, Billy Horschel 68-70-73