-16 B Davis (Eng) B Molder (US) -15 Z Johnson (US) -14 B Crane (US), J Overton (US), J Bohn (US) Selected others: -10 KJ Choi (Kor) -8 M Laird (Sco), P Casey (Eng) -6 V Singh (Fiji) level J Rose (Eng), J Daly (US) +1 I Poulter (Eng)
Davis has never won on the US Tour
England's Brian Davis is tied for the lead with American Bryce Molder going into the final round of the Crowne Plaza Invitational at Colonial.
Davis was third overnight, two strokes behind leader Molder, but carded his second straight bogey-free 65 to get to 16 under overall.
American Zach Johnson (64) was one shot back, alone in third.
Korean KJ Choi was on his way to a 62 but a quadruple-bogey eight on the 18th gave him a 66 to lie six off the lead.
Davis's blemish-free round included birdies at six, nine, 10, 14 and 17, while Moulder recovered from a double bogey on the fifth to finish with eight straight pars on his way to a 67.
Davis has missed the cut in his last three tournaments, but will be hoping to win his first ever US Tour title when he tees off at the Fort Worth course in Texas on Sunday.
The Londoner was pipped to victory by Jim Furyk at the Verizon Heritage last month after calling a two-stroke penalty on himself on the first play-off hole.
"What happened during the playoff threw me off balance a little bit," Davis admitted. "I lost my focus. ... Missing three cuts in a row, I wasn't exactly happy coming in.
"I've had to adjust my thinking a little bit. Not everybody can play well every week. You have to take the rough with the smooth some times."
The leaders' nearest rival, Johnson, sank six birdies for an impressive 64, although his compatriots Lee Janzen (11 under), Jerry Kelly and Pat Perez (both 10 under) went one better for rounds-of-the-day 63.
After seven birdies and an eagle, Choi was on target for a superb round.
But after he drove badly left on the par-four 18th, he found the water with his third shot, and missed the green with his sixth before eventually sinking an eight-yard put for a 66.
England's world number eight Paul Casey also carded 66 for eight under, the same score as Scot Martin Laird, while Ian Poulter, ranked sixth in the world, was last of those who had made the cut at one over after a 73.