The course record at Detroit Golf Club was threatened, tied and then finally toppled on Thursday at the Rocket Classic.
After budding Australian star Min Woo Lee carded a 9-under-par 63 to match the course record, it came down when Aldrich Potgieter of South Africa wrapped up a 10-under 62.
Just minutes after Potgieter's round was complete, Kevin Roy also signed for a 62. They carry a one-shot lead in the tournament into Friday.
By day's end, the old record looked like child's play, as Mark Hubbard and Max Greyserman also finished up with 63.
Potgieter got off to a white-hot start, shooting a 7-under 29 on the back nine with five birdies and an eagle. He added birdies at Nos. 1, 7 and 8 and nearly made it a 61 with another birdie at No 9 that missed by inches.
"I (thought it was going in), I started walking after it," Potgieter said. "But it was a good putt, I'm happy with it. And it was on a crest so I didn't know if it was going to be left or right, so it was just a little unfortunate but I'll take the 62 still."
Roy finished his round eagle-birdie to match Potgieter's number. Roy chipped in for eagle from 30 feet at the par-5 17th hole and then stuck his approach at No 18 to about 5 feet to set up his final birdie.
"Just one of those days everything was clicking," Roy said. "Lot of fairways, lot of greens, putter got hot, bonus chip-in on 17 for eagle. It's just when you've got it going, it's a lot of fun to try to keep it going. Yeah, just really happy with it."