Golf:Jason Dufner remains on course for a second straight tournament win after taking a two-stroke lead at the halfway point of the Crowne Plaza Invitational at Colonial in Texas.

Dufner, also bidding for a third win in five weeks following his success at last week’s Byron Nelson Championship, fired a bogey-free six-under round of 64.

Dufner had an 11-under 129 total at Hogan’s Alley, with first-round leader Zach Johnson slipping to second after a 67.

Bo Van Pelt and Tommy Gainey were third at seven under after Van Pelt shot a 64 and Gainey a 67.

Johnson had his 14th consecutive sub-par round at Colonial, one more than Van Pelt but defending champion David Toms missed the cut after shooting rounds of 74 and 71.

Dufner admitted he aimed to continue to show the good form which had put him in place to secure another win.

“My mindset is just to continue to play well and to be confident with it, admitted Dufner. “If I play some bad shots I just have to realise that I’m playing good golf and continue to run with it.”

Dufner revealed slightly stronger winds had made the second round tricky.

“I had a really nice day again today. The winds were up a little bit this morning which made it a little bit more difficult.

“I had another solid day. I kept the ball in play pretty well. I made some putts and all in all I had another great day.

“It’s been a good stretch of golf and I look forward to playing the weekend.”

In fifth is Tom Gillis, with fellow Americans Ryan Palmer and Harris English tied sixth and Rickie Fowler, John Huh and Ryan Moore sharing eighth.