But Turnesa overcame the gaffe by holing a 9-iron from 159 yards for eagle on the par-4 18th.

Turnesa's tumultuous conclusion capped a 9-under-par 64 that gave the 30-year-old PGA Tour rookie a share of the second-round lead with Matt Kuchar in the Justin Timberlake Shriners Hospitals for Children Open.

"What can I say?" Turnesa said. "I was a little disappointed (with the double bogey), but I just tried to make birdie to finish up.

"I knew I had hit it well, and when it went in and I heard the crowd roar, that was a good feeling. I've missed my last two cuts, so I didn't come here with any expectations. It's a great two rounds, but there's two rounds left."

Kuchar, a shot back of co-leaders Turnesa and Zach Johnson heading into Friday, turned in his second consecutive 63.

"It's not often you can follow up a 63 with another 63," said Kuchar, who played the final seven holes of his bogey-free round in 5 under. "You've got a stretch there of some birdie opportunities, a driveable par 4 and a reachable par 5. I strung together a couple of nice ones."

Johnson was a shot back at 17 under. He wasn't able to duplicate his first round, but Friday's 65 left him in striking distance.

"I actually thought I would be further back," Johnson said. "These conditions, which quite frankly feel like you're playing in a dome, are very benign. I was able to make some birdies on the back, and hopefully that will give me some momentum going into the weekend."

John Mallinger was two shots off the lead. He closed out a 64 with three consecutive birdies.

Pat Perez (63) and Ken Duke (66) were at 15 under, and former UNLV star Ryan Moore (64), Chez Reavie (66) and Chris Stroud (65) were at 14 under.

But, on another day of ideal conditions that yielded numerous low scores, it was Turnesa's wild finish that had people shaking their heads in amazement.

Seeking his first PGA Tour victory, Turnesa said he can't afford to change his approach just because he's out in front.

"I'm trying to be aggressive while smart at the same time," Turnesa said. "There's a lot of birdie opportunities out there, but you can also get into trouble on a few holes. So you just can't go for it all the time."

With such low scores being posted, Kuchar said there's little room for being conservative.

"Who knows what the magic number will be?" he said. "You can't let up. The mindset is you're going to have to keep the accelerator down."

Contact reporter Steve Carp at scarp@ reviewjournal.com or 702-387-2913.