Whee Kim fired a course-record-tying, 8- under 64 Thursday to grab a 1-stroke lead after the first round of the Chile Classic.
Kim tied for 11th place last week in Colombia in just his second career start on the Web.com Tour.
Edward Loar and Scott Harrington share second place at minus-7 at Prince of Wales Country Club.
Brendan Pappas posted a 6-under 66 and was joined in fourth place by Josh Broadaway, Felipe Aguilar, Brice Garnett and Philip Pettitt, Jr.
Former U.S. Amateur champion Danny Lee and brothers Michael and Andrew Putnam are among 13 players tied for ninth at 5-under 67.
Kim, 21, flew out of the gate by holing a wedge shot for eagle on the par-4 10th.
"My caddie and I talked and we said to carry it about 84 yards," Kim stated. "It bounced maybe one or two yards with backspin. It was lucky, but I played well on other holes."
He followed with a birdie on No. 11. Kim parred his next two before converting three birdies in a 4-hole span from the 14th to jump to 6-under through eight holes.
The Korean parred three in a row around the turn. He moved to 7-under with a birdie at the par-5 third, but gave that stroke back when he bogeyed the sixth.
Kim, who led after the second and third round at PGA Tour Q School last year, closed his round in style as he birdied the final two holes.
"I had a good start. I played very comfortable today. It was pretty easy. I had good tee shots and good iron shots and I putted good," Kim said. "Everything was good. Today was my day."
Loar, who won in Panama last year, ran off three birdies in a 4-hole span from the third. He made eagle at the par-5 ninth to make the turn at 5-under.
The 35-year-old tripped to a bogey at No. 10. Loar rebounded with four consecutive birdies from the 11th to jump to 8-under. He faltered to bogeys at 15 and 16, but birdied the 17th to grab a share of second place.
"A lot of my friends and family call me ROY-G-BIV for the colors of the rainbow. There was a lot of fun going on. I got a little aggressive on a couple holes and made some bogeys, but I also made a lot of birdies," said Loar, who didn't make a par in a 9-hole span from the ninth to 17th.
Harrington's round was much calmer by comparison. He birdied three of his first four holes from the first. After six straight pars, the 32-year-old again carded three birdies in a 4-hole stretch from the 11th. Harrington closed with a birdie at the last to end one back.
NOTES: Last year's winner Paul Haley II, Joseph Bramlett and Alex Coe each shot 64s in 2012 ... Haley is not in the field this week ... Bio Kim, no relation to the leader, eagled the ninth and 10th, making him the first player this year on the Web.com Tour with back-to-back eagles.