Chris Kirk carded a third-round 68 to take a one-shot lead into the final day of the Players Championship in Florida.
The American enjoyed a fine start to Saturday's session, holing three birdies in a bogey-free front nine at Ponte Vedra Beach.
Back-to-back bogeys on 13 and 14 threatened to scupper his round, but Kirk, bidding for his fourth PGA Tour win, recovered with three successive birdies to move to 10-under par for the tournament.
Kirk holds a slender one-stroke advantage over compatriots Kevin Kisner, Ben Martin and Bill Haas, all of whom head into the final day on nine-under par.
After disappointing rounds of 73 and 70 on Thursday and Friday, Justin Thomas fired a 65 to put himself in contention for the title - one of six players on eight under.
Meanwhile, British hopefuls Rory McIlroy and Ian Poulter both carded 70s to sit four strokes off the pace, with seven other players joining the duo on six under.