Fort Worth, Texas • Zach Johnson stood behind the fourth green looking at his club and then the ball that rolled within 4 feet of the hole.

"I got lucky," Johnson said about his second shot on the 244-yard par 3 — his 13th hole Thursday — after his tee shot went through the green and stopped in a clump of grass.

Three holes later, Johnson was so deep in a greenside bunker that he couldn't even be seen from the other side of the green until he popped up to watch his blast over the ridge to 21/2 feet from the cup.

Those par-savers were part of a bogey-free 6-under 64 that gave him a one-stroke lead after the first round in the Colonial, where 20- to 30-mph wind with higher gusts whipped through the big oak trees lining the fairways.

"Today was great. I got off to a good start, just hit some quality shots. I didn't put myself ever in a position that was too worrisome," Johnson said. "I kept the golf course in front me. I attacked when I could attack. I had a couple of nice saves when I needed it. … I've got zero complaints."

Jason Dufner, rookie Harris English, Tom Gillis and Kyle Reifers were tied for second.

Dufner started at Colonial with three consecutive birdies, was 5 under after a 10-foot birdie putt at the 174-yard eighth hole, then overcame two bogeys in a three-hole stretch.

Johnson opened with a 40-foot birdie putt at the 396-yard 10th hole on way to his 13th consecutive under-par round at Hogan's Alley.

Senior PGA Championship

Benton Harbor, Mich. • Roger Chapman shot a 3-under 68 to take the first-round lead in the Senior PGA Championship at difficult Harbor Shores.

The Englishman is playing only his second tournament of the year after tying for 16th this month in the European Senior Tour's Mallorca Open.

John Cook was a stroke back in the major championship, and Steve Pate, J.L. Lewis, Jeff Sluman, Jay Haas, David Frost and Jim Carter followed at 70.

Bernhard Langer and Mark Calcavecchia shot 73. Fred Funk, coming off a victory May 6 at The Woodlands in the last Champions Tour's event, had a 74. Fred Couples and Tom Lehman shot 76.