An Byeong-hun will take a one-shot lead into the final round of the Phoenix Open, after continuing his impressive week in Scottsdale with a bogey-free 65 on Saturday.
The 25-year-old South Korean, who has yet to win in 31 previous PGA Tour starts, shared top spot with Brendan Steele overnight, but pulled three clear by birdieing five of his first 10 holes.
Another gain came An's way on the 17th, lifting him to 16 under, but Martin Laird picked up shots on 13, 14 and 18 to match his playing partner's third-round score and sit just a solitary stroke off the pace.
Defending champion Hideki Matsuyama went round in 68 and is one of four players tied for third at 12 under - along with John Peterson, Graham DeLaet and Michael Kim.
DeLaet and Kim carded impressive scores of 65 and 66 respectively, but the performance of the day came from Peterson, who fired eight birdies and an eagle in a stunning 63.
His impressive score would have been better still had he not double-bogeyed the sixth.
Steele could only muster a one-under 70, which left him in a tie for seventh at 11 under with Marc Leishman (65), William McGirt (66), J.J. Spaun (67) and Matt Kuchar (69).
Phil Mickelson is one further back after a 65, while Jon Rahm - who claimed his first PGA Tour title at last week's Farmers Insurance Open - shot the same score to reach nine under.