Zach Johnson carded a second round of 66 to storm into a commanding lead at the halfway point of the Hyundai Tournamentof Champions in Hawaii.
Johnson was seven-under-par for the day as he burst through the congestion at the top of the leaderboard to take a three stroke lead on 13 under overall.
Dustin Johnson also shot a second round of 66 to grab a share of second place on 10 under alongside fellow Americans Matt Kuchar and Jordan Spieth.
Second round leaderboard
(US unless stated)
-13 Z Johnson
-10 D Johnson
-10 M Kuchar
-10 J Spieth
Behind them were Webb Simpson and Michael Thompson on nine under as only two of the 30-strong field finished the second day over par.
Johnson was one of eight players all within a shot of each other at the top of the leaderboard after round one, but on Saturday he moved clear in serene fashion.
He picked up a shot at the fourth, then birdied four straight from the sixth, eventually carding seven birdies in his round.
“The more I get my feet here, the more I walk these grounds, the more comfortable I become,” Johnson told the PGA Tour’s official website.
Dustin Johnson carded nine birdies against two bogeys in his 66 to head the chasing pack alongside Kuchar and Spieth.
The top 11 slots on the leaderboard were occupied by US golfers, with Scotland’s Martin Laird the leading European at three under par in 19th.