Tyler Duncan finds himself one shot ahead of the chasing pack going into the final round of the Safeway Open after carding an inconsistent round of 71 on Saturday.
After rounds of 65 and 66 at the course in Napa, California, the American birdied at the par-4 first but dropped shots on the second, seventh and eighth.
But Duncan was able to convert a ten foot putt after a 175-yard tee shot on the par-3 11th to remain in pole position.
Snapping at his heels will be Bud Cauley, who rose 12 places into joint third with a six-under round of 66 in which the American did not drop a shot.
Two sets of back-to-back birdies on the 8th and 9th, and the 13th and 14th, pushed Cauley into contention.
Among the standout shots was a deft chip from a bunker on the par-5 16th which led to an easy two-foot par for a birdie.
Phil Mickleson, 42 time PGA Tour winner, was also one of the big movers on day three, finishing his round tied for seventh with a four-under 68, leaving him four shots off the lead at 10 under.