Phil Mickelson has shot a bogey-free 4-under par 68 in his opening round of the Houston Open, showing no effects of the muscle pull that forced him to withdraw from last week's Texas Open.
The five-time major winner, who practiced at Augusta National for two days this week in advance of the Masters, is two shots in back of early leaders Keegan Bradley and Matt Kuchar; both finished at 6-under par 66.
J.B. Holmes is also at 6 under after 17 holes.
Mickelson and Bradley were part of a threesome with Webb Simpson, who also finished at 4 under.
All three players navigated the 7,441-yard Golf Club of Houston layout without a bogey.
Stewart Cink finished his morning round with a 5-under 67.