Jason Dufner positioned himself for yet another shot at his first PGA Tour title, shooting a 7-under 65 on Friday to take the second-round lead in the Zurich Classic.
Dufner, who lost a playoff for last year's PGA Championship and has three runner-up finishes in 163 winless starts on the PGA Tour, capped his bogey-free round with an eagle on the par-5 18th to reach 12 under at TPC Louisiana.
Russell Knox, John Rollins and Ken Duke were tied for second. Knox shot 64, Rollins 66, and Duke 68. Greg Chalmers also had a 64 to join Steve Stricker and Ernie Els at 10 under. Striker and Els shot 68.
Defending champion Bubba Watson had his second straight 71 to make the cut by a stroke in his first tournament since his playoff victory in the Masters.
Second-ranked Luke Donald was 6 under after a 65.