His efforts earned him a two-shot lead over Finland's Sami Valimaki on a rain-softened TPC Deere Run in Silvis, Illinois, so vulnerable to scoring that only 13 players in the 156-man field were over par.
Springer shot 27 on the front nine and tried to block out thoughts of a 59 or better.
Then he made five straight pars and figured the chance had passed until he holed a 55-yard shot for eagle on the par-5 17th.
Needing a birdie for golf's magic number, his approach caught the slope and left him 12 feet short. The putt was true all the way.
In December, Hayden Springer earned his PGA TOUR card via Q-School.— PGA TOUR (@PGATOUR) Today, he shot just the 14th sub-60 round in TOUR history 🤯 pic.twitter.com/UkEXk2MfalJuly 4, 2024
"(I'm) kind of at a loss for words," Springer said.
"That's one of the rare things in golf, so to have that opportunity and pull it off - it feels pretty special."
The PGA Tour record is a 58 by Jim Furyk at the Travelers Championship in 2016.
Any score that starts with a '5' remains special - although not quite as special as it once was as players get better each year.
Springer became the second player in three weeks to break 60, after Cameron Young's 59 at June's Travelers Championship.
Springer's effort tied the record at the TPC Deere Run: Paul Goydos shot a 59 in the first round of the John Deere Classic in 2010.
Valimaki, playing in the afternoon, noticed Springer's 59 as he played the front nine.
"I was like, 'OK, I need to keep shooting lower and lower', he said.
"I didn't catch it, but still a good round."
Eric Cole had a 62 to sit in outright third, while a group of four players tied for fourth at 63 included amateur Luke Clanton, who earned a share of 10th last week in the Rocket Mortgage Classic.
Harrison Endycott was the highest-placed Australian, his three-under 68 leaving him tied in 65th place.
Springer had reason to believe early this might be a special day: he holed a 12-foot eagle putt on the second hole and chipped in from 60 feet for birdie on the third.
He birdied the next three holes, with his putt from 15 feet on the sixth triggering thoughts of how low he could go.
"I was like, 'OK, I feel like I'm not missing today. I'm pretty much holing any putt I look at'," he said.
"That putt going in was kind of the trigger of, 'OK, we might be able to go super low'."
Springer became the fourth player on the PGA Tour with a 59 in the opening round.
Justin Thomas (Sony Open, 2017) and Brandt Snedeker (Wyndham Championship, 2018) went on to win.
The exception was Goydos at 2010's John Deere Classic.