German Matti Schmid had a bogey-free, 9-under-par 63 on Friday to overtake the lead at the World Wide Technology Championship in Cabo San Lucas, Mexico.
Schmid, seeking his first career win on the PGA Tour, took a one-stroke lead at 17-under 127 by pocketing seven birdies and an eagle at El Cardonal Golf Course.
He did that despite battling illness in recent days, limiting his preparation.
"I feel fresh and kind of short but good preparation I feel like," Schmid said. "Yeah, excited for the weekend."
His day began with five birdies over seven holes, before he took down the par-5, 585-yard No 18 in just three strokes to conclude his front nine.
"It was a really tricky putt, I had to kind of putt it up the ridge and let it come down," Schmid said. "I hit it kind of too hard but the bag was in the way, got a little lucky, but that's part of it."
Though cooling off over the back nine, the 10-time top-10 finisher still added two birdies to his total while remaining bogey-free.
"I kept life pretty stress-free out there today," he added.
Nick Dunlap and Finland's Sami Valimaki, who co-led Thursday after shooting bogey-free, 11-under-par 61s, remained tied with one another a stroke behind Schmid thanks to matching 67s.
Dunlap's day was going great with seven birdies over 14 holes until he ran into trouble on the par-4 No 7, taking a penalty and an eventual double bogey.
"I just hit it right, my only bad swing off the tee all week," Dunlap lamented. "This place gives you a lot of room off the tee but if you do miss it, then you're going to pay the price for it."
Valimaki didn't have anything quite so dramatic as that, instead balancing a pair of bogeys with seven birdies.
Chad Ramey (65) is alone in fourth at 15 under following his bogey-free round that included seven birdies.
A stroke behind him are France's Victory Perez (65) and Griffin (65), the latter of whom scored an eagle on his first hole of the day.
Tied for seventh at 13 under are Trevor Cone (64) and Mason Andersen (66).
Another six golfers are tied for ninth at 12 under: Eric Cole (63), Justin Lower (65), Carson Young (65), Taylor Moore (65), Italy's Francesco Molinari (67) and Patrick Rodgers (65).
Notable players who missed the cut of 5 under par included Brandt Snedeker (4 under), Wyndham Clark (3 under) and Englishman Luke Donald (3 under).