England's Brian Davis has joined Phil Mickelson at the top of the leaderboard at the Deutsche Bank Championship after both men carded 63 for their opening rounds at TPC Boston.
The 39-year-old Londoner, who now resides in Orlando, Florida, finished with two birdies to earn a share of the lead with the five-time Major champion.
Starting at the 10th, Mickelson navigated his front nine in seven-under par but his hot streak cooled on his way back in, although he did manage to get to nine-under.
However, a drop at the par-four ninth - his final hole - saw him fall back to eight-under.
Kevin Stadler is on his own in third place on seven-under, while Hunter Mahan, Sergio Garcia and Roberto Castro lurk on six-under.
Lee Westwood, Jason Dufner, Ian Poulter, Matt Kuchar and Ernie Els are part of a 14-strong group on five-under.
