AVONDALE, La. -- Jason Dufner is in familiar territory atop the leaderboard after 36 holes.
It's the weekend that has given him fits.
Dufner moved into position for another bid to win his first PGA Tour title, shooting a 7-under 65 on Friday to take the second-round lead in the Zurich Classic.
The former Auburn player has had at least a share of the 36-hole lead in two of his past four tournaments, including the Masters, where he closed with consecutive 75s. He's second on the tour in pre-cut scoring, but 98th in third rounds and 108th in final rounds.
"It's been a difficult weekend for me the last month and a half or so," Dufner said. "I haven't quite played as well as I would have liked, but I know that my game is still pretty good.
"I've been trying to think about what I can do better mentally, what I can do better emotionally out there and learn from some things that I maybe struggled with. Obviously, there's a lot of different things that go into winning besides hitting the golf ball."
On Friday, he capped his bogey-free round with a 30-foot eagle putt on the par-5 18th to reach 12 under.
"I had a couple of easy birdies," Dufner said. "I don't think I missed a fairway or a green. Just had some tough reads. The greens are kind of tough to read. Sometimes you get competing grains, competing slopes, so you get a putt that might break to the right, but the grain is going left. That can be kind of difficult to judge. Then 18, I had just a really good number for my 5-wood to get somewhere on that green and had a putt that was down grain and breaking to the left with the grain, so that was a nice way to finish the day."
Knox and Chalmers matched the course record.
Defending champion Bubba Watson had his second consecutive 71 to make the cut on the number at 2 under in his first tournament since his playoff victory in the Masters.
Knox, a Nationwide Tour graduate playing in his ninth tournament, had seven birdies and an eagle -- on No. 18 -- along with one bogey.
"You never plan on shooting a 64, it kind of happens and I'm happy it did," Knox said. "I haven't played well this year so far, but it's been the best year of my life."
Stricker had four consecutive birdies beginning on the seventh to move into a tie with Dufner, then missed a 2-foot birdie putt on the 11th that would have given him sole possession of the lead. Stricker stumbled home with bogeys on the 12th and 15th.
"I played really solid all the way through 11 and then missed that putt and kind of lost my thought process there for a little bit," Stricker said. "Felt like I let a really good one slip away today."
Donald also holed out from the fairway on the first hole, marking the first two eagles on the hole since the tournament was first played at the course in 2005.
Watson, away from his wife and recently adopted son after taking a two-week break following the Masters, eagled the seventh and birdied the eight, but bogeyed the 10th when he missed the green from 47 yards on his approach. He also three-putted the 12th for another bogey, moving him to 1 under, one above the cut line.
"Mentally, I've lost focus just about every shot, so I'm trying to figure it out," Watson said. "I want to be home with my son and wife. I know it sounds like a cop-out but I'm not playing very good because I'm just really not into it."
Watson also struck a fan in the head with a hooked drive.
Watson's tee shot on the second hole at the TPC Louisiana drew blood from the back of Radd Leonard's head.
Leonard, who was reached quickly by medics, said he was fine and found it incredible that he was hit in the head by the very player he came to see. The 52-year-old motorcycle shop owner from Baton Rouge also was glad he was able to help Watson back into the fairway, where the ball landed after striking him.
"I saw it coming and it looked like it was hooking right at me. I wanted to see that big hook, you know, and I got to see it. I turned and ducked and it still hit me," Leonard said. "It gave him a good bounce, anyway."
Watson walked over toward Leonard, put on a new golf glove, signed it, then took it off and gave it to Leonard and shook his hand. Watson's caddie, Ted Scott, drew laughter when he instructively pointed farther down the fairway and said, "We're glad you're all right, but if you could just angle your head a little differently ..."
John Daly, playing on a sponsor's exemption, missed the cut. He followed his opening 73 with an 80.