Dufner leads at Colonial

Jason Dufner fired a second-round of 64 to top the leaderboard at the midway point of day two at Colonial, Texas.

Dufner, winner of last week's Byron Nelson Championship, finished on six under par - 11 under in total - after he claimed a hat-trick of birdies on holes one, two and three.

The American leapfrogged overnight leader Zach Johnson who started later in the day and was two shots behind after 11 holes.

Bo Van Pelt moved up 17 places into third after a six-under-par round today to tie with Harris English and Tommy Gainey midway through their rounds.

Jim Furyk started well with a score of five under par on the back nine to move up into seventh after a strong start.

The 2003 US Open champion shot four birdies and a bogey before he scored an eagle on the par-five first hole.

Rickie Fowler and John Huh were tied in ninth place on four under par, while further back there was a seven-way tie for 11th place, although Kevin Chappell, Andres Romero and Kyle Reefers were the only finishers in that group.

Greg Owen was the best-placed Englishman on one under par for the day after eight holes following a birdie on the first and fifth and a bogey on seven.