Brian Harman will go into the final day of the Travelers Championship with a one-shot lead after a bogey-free third round of 65 in Connecticut.
The 28-year-old American, whose only previous win on the PGA Tour came at the John Deere Classic last July, bookended his round with birdies, with his three on the par-four 18th following an excellent approach to three feet helping him to 14 under and the outright lead.
The left-hander also picked up shots at the seventh, 10th and 13th for his second successive five under par round which moved him ahead of compatriot and two-time Masters champion Bubba Watson and Canada's Graham De Laet, who shot a fine 64.
De Laet, chasing his first career PGA Tour win in 122 starts, began the day four shots off Watson's lead.
He caught the big-hitting American at the short par-four 15th where he drove the green and holed a short eagle putt but was left to rue leaving an 18-foot putt short at the last as he signed for a 64 at 13 under.
Watson bounced back from a bogey at the 12th to birdie the next and he was joined in a three-way tie at the top when Harman, playing alongside the left-hander, also birdied the hole.
Watson had a stroke of luck when a huge hook at the 15th took a kindly bounce out of the trees and into a bunker short of the green from where he escaped with par.
De Laet, Harman, Chris Stroud and Patrick Rodgers currently hold the four places for Open qualification.
England's Paul Casey put himself in contention with a six-under 64 to move to 11 under.
Sergio Garcia is in a tie for eighth alongside four others after a 66, which included six birdies and a double bogey at the par-five 13th after the Spaniard found water with his tee shot.
Luke Donald is two shots further back overall on seven under after a 67, his best round of the week, while Scotland's Martin Laird is on six under.