LOS ANGELES (AFP) — Reigning US Amateur champion Nick Dunlap fired a stunning 12-under par 60 to seize a three-stroke lead after Saturday's third round of the PGA Tour American Express tournament.

Dunlap, a 20-year-old sophomore at the University of Alabama, made 10 birdies and an eagle at La Quinta Country Club — one of three courses used in the first three rounds — to stand on 27-under 189 after 54 holes.

Filipino-American Rico Hoey carded an even-par 72 but still failed to make the cut. He was 11-under after three rounds — 16 shots behind the leader — and joined the likes of Rickie Fowler who didn't advance.

"It was a blast," Dunlap said. "The putter felt so good. The hole looked like a funnel… just kind of kept putting shots together and ended up with a pretty good round.

"I made a lot of putts. The putter felt really good. I don't think I missed anything that I should have made. Drove it well. Hit the irons really good. I don't have any negatives after that round. I did everything pretty well."

Compatriot Sam Burns was second on 192 with fellow American Justin Thomas third on 193 and South African Christiaan Bezuidenhout fourth on 195.

American prodigy Dunlap could become the first amateur golfer to win a US PGA Tour event since Phil Mickelson captured the 1991 Northern Telecom Open in Tucson, Arizona.

Dunlap would also become the second-youngest winner of a PGA event in the past 90 years, trailing only Jordan Spieth's victory at 19 at the 2013 John Deere Classic.

Dunlap would not take home the winner's prize of $1.51 million, which would slide to the runner-up should Dunlap be victorious.

But he would become eligible to take PGA Tour membership at any time in the 2024 PGA campaign and receive the benefits of any PGA Tour winner, which include membership through the 2026 season, entries into the Masters and PGA Championship and any unplayed "signature" events.

"Definitely nervous," Dunlap said. "Pressure is a privilege and I'm fortunate to be in the spot I'm in.

"It's going to be hard. It's going to be something I haven't experienced yet.

"We've got a good game plan for that golf course and just kind of go out there and do us, stay in the present and go from there."

Dunlap already has berths in this year's Masters, PGA and British Open after his US Amateur triumph, provided he remains an amateur when the events are played.

Dunlap, who fired a 64 at the Nicklaus course and a 65 at the Pete Dye course in the first two rounds, began on the back side at La Quinta and reeled off four birdies in a row starting at the par-5 11th.