Dufner one clear in New Orleans
Jason Dufner fired a superb 65 to climb to the top of the leaderboard at the Zurich Classic of New Orleans at 12-under-par.
The 35-year-old enjoyed a flawless round and, after carding five birdies, he capped it off with an eagle at the 18th hole to put himself in pole position at the halfway stage to land his maiden PGA Tour title.
Dufner, who was beaten in a play-off at the USPGA Championship last year, holds a one-shot lead over the field with 36 holes to play.
Scotland's Russell Knox carded a sensational round of 64, which included an eagle, seven birdies and one bogey, to move into a share of second place alongside the American pair of John Rollins (66) and Ken Duke (68) at 11-under.
One shot further back are the big guns of Steve Stricker and Ernie Els, who both carded rounds of 68, as well as Australian Greg Chalmers, who matched Knox's effort of 64.
Elsewhere, Luke Donald, who needs to finish in the top seven to regain the number one world ranking, got himself back into contention with a fine 65 to move to six-under-par, six shots off the pace, while defending champion Bubba Watson survived the cut with no room to spare with a second successive 71.