Brian Harman opened up a three-stroke lead at the Sony Open in Hawaii after carding a seven-under 63 in the second round.
The American eagled the par-five ninth - his final hole of the day - to move into 13 under at the Waialae Country Club in Honolulu on Friday.
Harman had been solid before making three straight birdies, beginning at the second.
He reached the green in two at the ninth, making a 17-footer for eagle for a perfect finish to his round.
Harman is three shots clear on what is a congested leaderboard, with Zach Johnson (67), John Peterson (64), Tom Hoge (65), Chris Kirk (67) and Talor Gooch (66) at 10 under.
Patton Kizzire (64), Ollie Schniederjans (65) and Kyle Stanley (67) are a further shot back.
Defending champion Justin Thomas posted a second straight 67 to be tied for 17th at six under.
The US PGA Championship winner made two birdies and an eagle - at the ninth - to finish his round.
Three-time major champion Jordan Spieth was unable to climb into contention, firing a two-under 68.
The American did produce one of the shots of the day with an incredible 91-foot birdie putt at the fifth, but he is at three under and tied for 48th.