American Zach Johnson has opened up a three-shot lead after the second round of the Hyundai Tournament of Champions in Hawaii.
Johnson started Saturday one shot off the pace in a tie for second but lit up the course at Kapalua with a flawless round of 67 on Saturday.
The 37-year-old had four birdies on the front nine – including three straight at six, seven and eight – before adding another three on the way home to get to 13-under overall.
Johnson's round was matched by his namesake, with compatriot Dustin Johnson also hitting a 66 to move to 10-under par.
He is joined in a tie for second with Matt Kuchar (68) and Jordan Spieth (70), with Michael Thompson (71) and Webb Simpson (71) a shot further back at nine-under overall.
Americans make up the first 11 players on the leaderboard with Ryan Moore, Kevin Streelman (both eight under), Brandt Snedeker, Ken Duke and Jason Dufner (all seven under) all within striking distance of the leader.
Masters champion Adam Scott is in a tie for 12th after a second consecutive three-under 70, one ahead of a trio of Americans Gary Woodland (70), Harris English (71) and Chris Kirk (75).
Scott is one of just four non-locals in the 30-man event, alongside South Korea's Bae Sang-Moon (tied 16th), Scotland's Martin Laird (19th) and Sweden's Jonas Blixt (tied 25th).
Derek Ernst continued his struggles with the Plantation Course, shooting a second-round 76 to go with his first-round 79 to be last at nine-over overall, and eight shots off the 29th-placed John Merrick.