Jason Dufner fired a five-under 67 Saturday to push his lead to two strokes after three rounds of the Zurich Classic of New Orleans.
Dufner completed 54 holes at 17-under-par 199 and is two strokes clear. He will go for his first PGA Tour title on Sunday.
He won't have history on his side, though. He led after 36 holes at the Masters and was one stroke back after two rounds at the Arnold Palmer Invitational. However, Dufner shot six-over 150 on the weekend both times to fall out of contention.
Canadian Graham DeLaet had a six-under 66 to climb into second place. He finished three rounds at 15-under-par 201 at TPC Louisiana.
Ernie Els (68) and John Rollins (69) share third place at minus-14.
Ryan Palmer matched the course record with his eight-under 64. He was joined in a share of fifth place at 13-under par by Steve Stricker (69) and Cameron Tringale (68).
Masters winner and defending champion Bubba Watson fired a seven-under 65 to soar 47 spots into a share of 16th at minus-nine.
Dufner opened with a tap-in birdie on the first. He poured in a 51-footer for birdie on the fourth and made it two in a row with a 23-foot birdie putt at the fifth.
At that point, he was two clear of Rollins, who birdied two and three. Dufner duffed a chip on the par-four sixth and that led to a bogey.
He atoned for that error with a five-foot birdie putt at the seventh. Dufner ran off seven consecutive pars from the eighth, and that let Rollins and DeLaet back into contention.
Rollins followed a birdie on No. 7 with another birdie at the eighth. He faltered to a bogey on No. 9, but he drained a 15-footer for birdie on the 12th to join Dufner in the lead at 15-under.
DeLaet birdied the second, then drained three birdies in a four-hole span from the seventh. He stumbled to a bogey on the 12th, then birdied three of the next four holes to join Dufner and DeLaet in the lead.
The Canadian parred the final two holes to end at 15-under.
"You've obviously got to make a few putts to shoot six-under par, but it was a good day," DeLaet said in a televised interview. "I've been feeling good about my game even though my results haven't been there."
Rollins tripped to a bogey on 17 to fall to 14-under. He has three top-10 finishes this year, but has missed the cut in five of his last seven starts.
"This golf course has been good to me. I've played well here in the past," Rollins said in a television interview.
Dufner pulled away down the stretch. He dropped his approach within two feet at the 15th and tapped that in for birdie and the lead. Dufner had 11 feet for eagle at the last, but left the putt short. He kicked in his birdie putt to extend his lead to two after 54 holes.
"I just had a nice solid round. Usually on Saturday guys tend to go low and push towards that lead, so you've just got to stay patient," Dufner said in an interview with Golf Channel. "I knew there were a couple birdie holes coming in.
"Today's not the end of the tournament and the guys were pushing at me. I know what's on the line and I'm in great position through three rounds. I just need to stay focused and maybe act like it's a Thursday, and then see where we're at on the back nine."
Dufner will need that good attitude on Sunday since he is tied for 108th on the PGA Tour in final-round scoring average. He has broken par in just three of eight final rounds this year. Dufner's 68 at the Humana Challenge was his best final round in 2012.
NOTES: Watson's 47-spot move was the biggest of the day...With 79 players making it to the weekend, eight players missed the 54-hole cut as 71 players will play the final round...Scott Verplank, who owns the tournament's 36- and 54-hole scoring records, and 2006 champion Chris Couch were among those missing the 54-hole cut.