Sizzling Dufner surges four ahead at Colonial

In-form Jason Dufner remained on track for a third PGA Tour victory in four weeks by surging into an early four-shot lead in Friday's second round of the Colonial Invitational in Fort Worth, Texas.

The laid-back American, who won his second title on the U.S. circuit at the Byron Nelson Championship on Sunday, fired a flawless six-under-par 64 on another hot and breezy day at the iconic Colonial Country Club.

"I just feel really comfortable with my game," Dufner told reporters after reaching 27 of 36 greens in regulation over the first two rounds.

"I've said it now for a couple of months, when I step on to the first tee I feel like I'm going to play a good round of golf. That's a nice way to play golf. It's a comfortable way to play golf."

Dufner covered his last nine holes in a sizzling four-under 31 to post an 11-under total of 129, four better than compatriot Bo Van Pelt (64).

Fellow American Tom Gillis (69) was a further stroke back at six under while first-round leader Zach Johnson, who had opened with a 64, was among the day's late starters.

Dufner, who needed 164 PGA Tour starts before clinching his maiden victory at the New Orleans Classic four weeks ago, continued where he left off on Thursday after shooting a 65.

A stroke behind the pacesetting Johnson overnight, the 35-year-old birdied the 13th and 17th to take over at the top after teeing off at the par-four 10th.

Dufner then picked up further shots at the first, second, third and fifth, where he rolled in an 18-foot putt, to cement his status as the hottest player in the game.

Rickie Fowler, who clinched his maiden PGA Tour victory at the Wells Fargo Championship three weeks ago, summed up Dufner's dominance after playing with his fellow American in the first two rounds at Colonial.

"We're going to have to play catch-up this weekend," smiled Fowler after shooting a second successive 68 to finish seven strokes behind Dufner.

The cut was projected to fall at two-over 142 with former PGA Tour winners J.J. Henry, Johnson Wagner and Kyle Stanley, plus exciting Japanese talent Ryo Ishikawa, among those likely to miss out.

(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)