Dufner edges ahead in Irving

Jason Dufner leads the Byron Nelson by one stroke at the halfway stage following a second round four-under 66.

Dufner's round burst into life after he was on level par for his first 13 holes, which included three birdies and three bogeys, as he fired birdies at the 14th, 15th, 16th and 18th to go seven under for the tournament. "It was a nice way to finish," Dufner told www.pgatour.com. "[I'm] looking forward to the weekend." First round leader Ryan Palmer finished a shot further back alongside Chad Campbell, who equalled Dufner's four under. Matt Kuchar, Pat Perez, Dicky Pride and Australia's Marc Leishman, the only non-American in the top seven, make up the group on six under going into Saturday's third round in Irving. Ireland's Padraig Harrington is the best-placed European at the halfway stage on three under, while England's Brian Davis had a best-of-the-day five-under 65 to sit two under overall.