Mackenzie Hughes fired 11 birdies in a sizzling nine-under par 63 on Thursday to take a one-stroke lead over Ryder Cup-bound Ben Griffin and Matt McCarty in the US PGA Tour Procore Championship.
Hughes, a two-time winner on the PGA Tour, admitted thoughts of a 59 "crossed my mind for a second," but after bogeys at 14 and 15 he had to settle for the first-round lead at Silverado Resort in Napa, California.
The Canadian got to work early with birdies at the second and third and then began to "pile it on" with birdies at the fifth and sixth and three in a row at eight, nine and 10.
He was rolling with back-to-back birdies at 12 and 13, and after his miscues at 14 and 15 got back on track with birdies at 16 and 18.
"I had a nice feel with the putter, so it was really just about continuing to put my foot on the gas and go forward," Hughes said. "I did some really nice things.
"On 12 I drove it right and had to kind of pitch back to the fairway and I got up and down from 225 yards for birdie. So I did some stuff that you can't really count on all the time."
Hughes is making his first start since the FedEx Cup playoffs in August as the tour's Fall series of events kicks off.
Normally stacked with players jockeying to improve or secure their playing status for the next season, this year's Napa stop is serving as a warm-up for most of the US Ryder Cup team to take on Europe in the biennial match play showdown later this month.
Griffin, who won twice this year and was a captain's pick for his first Ryder Cup team, was the best of the Ryder Cup bunch on Thursday.
He had eight birdies and rolled in a 17-foot par-saving putt at the 18th to join McCarty, who also had eight birdies without a bogey in his 64.
World No 4 Russell Henley, who will also head to Bethpage Black in New York as part of Keegan Bradley's US Ryder Cup team, was tied for fourth on 65 alongside Lanto Griffin.
Henley opened with back-to-back bogeys but responded with a vengeance, picking up birdies at six of the next seven holes. He added three more before a bogey at 16, but closed with his 10th birdie of the day at the last.
"I feel really good about how I'm hitting it off the tee," Henley said. "Felt like I was controlling my distances pretty well to the greens and I putted great.
"I felt good about my reads and felt like I was hitting my lines and hitting them solid, so it was awesome to see them go in," added Henley, who played alongside Ryder Cup teammates Scottie Scheffler and J.J. Spaun.
Spaun, the reigning US Open champion, carded a five-under 67 that left him tied for seventh.
World No 1 Scheffler, whose five titles this year included two majors, signed for a 70 that included four birdies and two bogeys.
"I think it was a pretty frustrating day overall," Scheffler said. "I felt like I did some things well out there, I just wasn't quite getting the reward."