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.

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 2 1/2 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 20-30 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 won the Byron Nelson Championship last week, and both of his PGA Tour victories have come in the last four weeks. He 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. He set the Colonial tournament scoring record with his 21-under 259 in 2010, when he had a pair of 64s in his last PGA Tour victory.

After hitting into a greenside bunker at the 435-yard 12th, he blasted to 9 feet to save par.

"The big putt that got me going," he said. He then had four consecutive birdies, a span that included two par 3s and all the putts between 14-21 feet.

Sergio Garcia, the 2001 Colonial champ in the same group as Johnson, shot a 66 to match Chris DiMarco, Tommy Gainey and Andres Romero.

The 22-year-old English, a winner last year on the Nationwide Tour as an amateur, has made 11 of 14 cuts in his first season on the PGA Tour.

Senior PGA Championship

At 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.