On a day of low scoring on Thursday, Ghim took a one-shot lead over Max Homa and Austin Eckroat at the TPC Deere Run, where the winning score has been 20-under par or lower 12 of the last 15 years.
He has been around long enough - six years on the PGA Tour, 160 tour starts as a pro - to know it's only a start. The conditions were so ideal Ghim wasn't even sure his 62 would hold up as the lead by the end of the day.
With a little more wind in the afternoon, the best anyone could do was 65 by four players, including Cameron Champ and Mexico Open winner Brian Campbell.
"Honestly, any time you can get to 20 under or better you're going to have a chance," Ghim said. "It's still golf. It's still a challenge. You have to hit fairways. I hit a lot of them today. So just trying to shoot forwards of six under every day and see where that puts me."
South African Aldrich Potgieter, the 20-year-old coming off his first PGA Tour win last week in Detroit, was challenging for the lead until he stalled at the end of his round, took bogey on the par-5 17th and had to settle for a 67.
The John Deere Classic has produced 24 first-time winners, the most of any PGA Tour event since 1970, a list that included Davis Thompson last year, Bryson DeChambeau in 2017 and Jordan Spieth in 2013.
Homa and Eckroat have won before, and both are trying to rediscover their games. Homa gets the most attention, particularly since he played in the last Ryder Cup and reached No.8 in the world until going into a slump that includes new equipment, a new coach and new caddie.
Eckroat won twice in 2024 but it has been a struggle this year. He ended last year at No.35 in the world and now is at No.75, leaving him out of the last two majors. He has yet to finish in the top 10 in 19 starts this year.
Homa ran off four straight birdies early and was tied with Ghim for the lead until he missed his final green at No.9 into a bunker and failed to get up-and-down, his only bogey of the round. Eckroat had a pair of eagles, one on the par-5 second with a shot to 12 feet, the other when he holed out with a gap wedge from 137 yards on the par-4 fifth hole.
Scoring was so low that 18 players were at 65 or better, and more than half of the 156-man field broke 70.
Australians Jason Day (74), Harrison Endycott (76) and Karl Vilips (77) were not among them. They find themselves in the bottom 20 of the field.
