Jonas Blixt matched his career-low 18-hole score with a 9-under 62, in spite of a bogey at the par-4, 5th to take a two-shot lead in the John Deere Classic.
The Swede made two eagles and six birdies and recorded his first sub-30 score for nine holes (29).
"I had six weeks off and worked a lot with my swing coach back home. I had struggled a lot I feel like a few months there, and I think I found something this week after playing the Korn Ferry last week.
"At this point when you don't have that much confidence in your game and you find something, you just kind of go out and see where you swing at it, and that's what happened. I mean, 62 doesn't happen very often on the PGA TOUR, at least not for me.
"I'm very happy about it. Extremely happy about it."
Blixt hadn't held the lead since the second round of the 2019 Charles Schwab Challenge.
"When you go through swing changes, sometimes there's a little bit of doubt in there. Today I got into a really good rhythm.
"I spoke to my swing coach. I mean, I feel it back there, and he said he never seen me swing this well. He has been with me since my college days. So that gives you a little bit of a confidence boost as well. You know, I'm just trying to go out swinging right now."
Grayson Murray posted a bogey-free 64, his lowest round on Tour since the 2020 American Express, and lies in solo second place at 7-under.
Fellow Americans Greyson Sigg, Adam Schenk, Nate Lashley, Richy Werenski and Cameron Young, as well as South Africa's Garrick Higgo are tied in third place at 6-under after closing with a 65, bogey-free except for Werenski and Young.
Greyson Sigg, Adam Schenk and Cameron Young are the only players at 6-under or better yet to win on Tour.
Sponsor exemption William Mouw (USA) posted a 66 for a share of 9th place at 5-under in his second PGA Tour start (he made the cut in the 2022 U.S. Open). He came into this week off four consecutive Korn Ferry Tour starts since turning professional, making the cut in each and posting all 16 rounds under-par.