John Mallinger equalled the course record to surge into the lead after the second round of the Frys.com Open in California.
Mallinger's nine-under 62 at the CordeValle Golf Club, repeating the feat of Nick O'Hern the previous day, put him four clear of Billy Horschel and Jhonattan Vegas.
Like O'Hern on day one, Mallinger was bogey-free for his round - indeed, he is without a blemish on his card so far this week - but he also threw in an eagle at the par-five 15th to go with seven birdies, putting him 14 under overall.
His nearest challengers, compatriot Horschel and Venezuela's Vegas were round in 67 and 65 respectively.
Overnight leader O'Hern could only manage a level-par 71, putting him in a share of fourth on nine under alongside Belgian Ryder Cup star Nicolas Colsaerts and Scott Dunlap of the United States.
Dunlap fired an eight-under 63, with seven of his eight birdies coming on the back nine as he came home in 29.
England's Greg Owen led the British challenge as his two-under round put him seven under overall and in a tie for ninth, three strokes ahead of Scotland's Russell Knox and American defending champion Bryce Molder.
Another Englishman, Brian Davis, scraped into weekend play on one under, making the cut with nothing to spare, but Gary Christian bowed out at the halfway stage.
With an exciting weekend in prospect, Mallinger is full of confidence as he chases a maiden PGA Tour victory.
"It's only the second time I've shot 62 in seven years out here, so it's not very often," said the California native.
"It's just one of those days where everything just kind of clicks and you just roll with it. I drove it great, irons were great, and made putts."
Mallinger lives in Long Beach and has found the greens this week to his liking.
"It's the same grass I practice on at home," he said. "I'm just real comfortable with the speed. I just have some good thoughts over the putter right now, and that's not every week.
"Hopefully I can take advantage of it and keep it going into the weekend."
Having twice finished as runner up in PGA Tour events, Mallinger believes he can go one further on the weekend.
"It's difficult. I've been out here six years and I haven't won yet. Been close a lot of times, lost in a playoff, had a bunch of third places," he said.
"I feel like I'm close. I don't think I would be up here if I wasn't. I'm not going to go into the weekend scared.
"I'm going to play as hard as I can and compete as hard as I can."