FORT WORTH, Texas (AP) - Dustin Johnson had played Colonial only once before, six years ago when he didn’t even make it to the final round.
In his return to Hogan’s Alley, Johnson took a one-stroke lead after the first round.
Johnson shot a bogey-free 5-under 65 on Thursday, driving a lot of 3-irons off the tees into the fairways and hitting 16 of 18 greens in regulation.
His only birdie on the back nine was a 2-footer at the 177-yard 16th hole. That was enough to lead after his front-side 31 that included a 45-foot birdie putt on the difficult par-4 fifth hole.
Jimmy Walker, a three-time winner this season, and 20-year-old Dallas native Jordan Spieth were in the group of 10 players at 67.
Mahan started eagle-birdie and was already 6 under after a 3-foot birdie on the 178-yard eighth hole. He had two bogeys and two more birdies before his drive at the 18th hole into the right rough, with trees blocking a clear shot to the green. After punching the ball back into the fairway, his approach came settled on the edge of the fringe and he eventually two-putted from 7 feet.
Adam Scott, playing as the No. 1 player in the world for the first time, shot 71 after playing his first nine holes at 4-over 39.
SENIOR PGA CHAMPIONSHIP
BENTON HARBOR, Mich. (AP) - Joe Durant birdied his final hole for a 6-under 65 and a one-stroke lead after the first round of the Senior PGA Championship.
Making his third Champions Tour start after turning 50 in April 7, the four-time PGA Tour winner had seven birdies and a bogey at Harbor Shores.
Dan Forsman, fighting an arthritic left hip, opened with a 66, and Brad Faxon had a 67. Mark Brooks and P.H. Horgan III shot 68, and two-time Senior PGA winner Jay Haas and Colin Montgomerie were in the group at 69.
Kenny Perry, the Regions Tradition winner last week in Alabama, topped the group at 70 along with Bernhard Langer, Tom Lehman, John Cook and Tom Watson.
Durant, coming off a ninth-place tie Sunday at Shoal Creek in the first major of the year, missed only one fairway and birdied all the par 5s. He also birdied the par-4 seventh hole that plays up a sand dune and usually into the wind off Lake Michigan.
BMW PGA CHAMPIONSHIP