Collin Morikawa shot a five-under-par 67 to move into a one-shot lead after the third round at the Arnold Palmer Invitational.
The world number five drained six birdies, including a putt from almost 12 feet on the last hole, to improve to 10 under overall.
That nudged Morikawa one shot clear of fellow American Russell Henley, who also fired a 67 at Bay Hill in Orlando on Saturday.
Canada’s Corey Conners trails Morikawa by two strokes heading into Sunday’s final round, with Australia’s Jason Day a shot further back in fourth.
Ireland’s Shane Lowry began the day with a two-shot lead over Wyndham Clark but slipped down the leaderboard, with a four-over 76 leaving him six adrift on four under.
Clark dropped back too, with the American also settling for 76 and falling to a tie for 13th.
Northern Ireland’s Rory McIlroy was another who lost ground, with his one-over 73 leaving the world number two in a tie for 10th with England’s Aaron Rai and Scotland’s Robert MacIntyre.
Henley made a statement by starting the back nine with four consecutive birdies, while Conners slipped back with a dropped shot at the 18th hole.
Michael Kim (67) and Tony Finau (68) moved into somewhat distant contention at five under, while Andrew Novak enjoyed the best round of the day as a bogey-free 65 moved him to four under.
Morikawa has not won on the PGA Tour since October 2023, and the 28-year-old has experienced mixed fortunes on this course in the past, recalling previous missed cuts following his round on Saturday.
“I’ve come to this event not playing great previously,” said the two-time major winner, “and it’s a course that if you’re not playing great it’s going to show.
“It’s just one of those that you can’t fake it. But this was one of my first professional starts as an amateur, I played in 2017, and I love the golf course.
“On a course like this you just have to have complete control of your golf ball, so that’s what it’s going to take tomorrow.”
He added: “I would say the guys that are winning on a constant basis, they’re playing free, and that’s how I’m going to go out tomorrow.”
