Zach Johnson has posted 66 for his second round at the Hyundai Tournament of Champions to open up a three-shot lead over Dustin Johnson.
The 37-year-old, who went around the Plantation Course in 67 yesterday, shot seven birdies without a single blemish on his scorecard, reaching 13-under-par for the championship.
His namesake, Dustin, also carded 66 and is level on 10-under-par with Matt Kuchar and Jordan Spieth.
Webb Simpson and Michael Thompson, who held a share of the lead overnight, are tied for fifth on nine-under-par, with Ryan Moore and Kevin Streelman - also co-leaders after day one - are a shot further back.
Brandt Snedeker and Ken Duke complete the top 10 on seven-under, although Jason Dufner is on the same score but misses out on a spot on the top page.
