Philip Knowles chipped in for three eagles and grabbed a share of the lead with fellow Americans Chris Kirk and Andrew Putnam after Friday's second round of the US PGA Tour Rocket Classic.
Knowles, ranked 519th in the world, fired an eight-under par 64 to match Kirk and Putnam on 14-under 130 for 36 holes at Detroit Golf Club.
"I got pretty lucky a couple times," Knowles said. "I hit quality shots that ended up going in the hole, but I can't imagine chipping in three times for eagle ever again in my life."
Back-nine starter Knowles, on a medical exemption after thumb and eye injuries the past two years, seeks his first PGA title after making the cut only twice in 11 prior starts this season.
"It has not been my best year thus far by any stretch of the imagination, but golf is funny," Knowles said. "When you're playing bad, you never feel like you're going to play good again, and when you have days like today, you just don't understand how you could ever shoot a bad round of golf.
"So it was super rewarding."
Knowles made his first eagle came at the par-five 17th, when he rolled in an 81-foot chip from the fringe.
At the par-five fourth, Knowles chipped in from the fairway from 37 yards and, three holes later on another par-five, he chipped in from the left rough from 40 holes.
"That was surreal," he said.
Putnam, who shot 66, birdied three of the first four holes then eagled the par-five seventh on an 88-foot chip-in from the fairway and got up and down from a bunker at 14 in his bogey-free round.
"It didn't feel like bogey free," Putnam said. "It felt like I was kind of all over the place on the back nine, but the front nine was pretty simple golf. Wind came up, got a couple tricky holes out there, so glad I could grind it out."
Kirk fired a 65, opening with three consecutive birdies and closing with back-to-back birdies. He seeks a seventh career PGA title and his first since last year's tournament of champions in Hawaii.
"Dream start for sure," Kirk said. "Then was able to add a few more. Back nine was a little bit more hit and miss... But I was in a really good rhythm. Proud of the way I hung in there and kept hitting good shots."
American Jackson Suber was fourth on 131 with countrymen Mark Hubbard and Michael Thorbjornsen and South African Aldrich Potgieter on 132.
Jake Knapp fired a course-record 61 to stand on 133, his bogey-free round with nine birdies and an eagle breaking the mark of 62 set Thursday by fellow American Kevin Roy and Potgieter.
It was the second course record of the season by Knapp, who fired a 59 at PGA National in the Cognizant Classic.
"I'm definitely not afraid of shooting a low number," Knapp said. "When I start making birdies, I want to make more."