Mixed start for Koepka as DeChambeau takes outright Augusta lead
Brooks Koepka made a hit-and-miss start to his second round at the Masters, while Bryson DeChambeau was leading by one from Phil Mickelson.
A six-under 66 on Thursday left Koepka in an overnight tie for the lead with fellow American DeChambeau.
Koepka birdied the first but found trouble in the trees at the second, taking an unplayable for his third stroke, and eventually missed a 27-foot putt for bogey.
The double bogey meant he was five under for the tournament through two holes.
DeChambeau had no such trouble and made birdie at the par-five second and was at seven under.
Veteran Mickelson - playing his 100th Masters round - was a stroke back and one under for his round through two. Ian Poulter was three strokes adrift, while Dustin Johnson was one over through three holes and in a group at three under with Matt Kuchar, Jason Day and Francesco Molinari.