Justin Sui (St. Augustine Amateur Photo)

Justin Sui of Lake Orion, Mich., shot a final-round 66 on Sunday to hold off local favorite Jason Duff of Elkton, Fla., by one stroke in the St. Augustine Amateur at the St. Johns Golf Club. Sui finished at 10-under and Duff at 9-under after a closing 67. Duff is a senior at North Florida.

Sui, 20, and Duff, 23, were tied at 5-under to begin the final round. Duff took a one-stroke lead at 7-under par with consecutive birdies on the third and fourth holes, but he gave those back with a double bogey on the drivable par-4 No. 6, hitting his tee shot in the water and another drive in a bunker to relinquish the lead after Sui got up and down for birdie on the hole.

Duff made a 40-foot birdie putt on the par-4 ninth to reach 7-under and was one shot behind entering the back nine. Sui made an eagle at the par-5 No. 11 hole to increase his lead to two, which held for most of the back nine as Duff made bogeys on 14 and 15. But Duff made it interesting with birdies on the par-4 No. 16 and par-3 No. 17. Sui was 10-under and Duff 9-under, walking to the finishing par 5.

Both players drove within 240 yards of the green, and both missed the green just to the left, leaving a chipping match for the title. Duff chipped 10 feet long in trying to hole it, and Sui left his chip and run six feet short. Both missed putts for the final verdict.

“When we got to the back nine, we both realized it was going to be one-on-one match play,” Sui said. “I knew I just needed to keep playing stable and match what (Duff) was doing. With the lack of wind today, you knew there were going to be some birdies.”

The victory was another highlight in Sui’s amateur career. His father, Shane, who also served as his caddie this week, came to the United States in 1995 from China as an automotive engineer and settled in Detroit. Justin developed a love for golf as a youth, playing American Junior Golf Association events in Michigan, and was a 2020 AJGA All-Star while graduating from high school at age 15.

He aimed to attend Harvard, but Covid kept him from that goal and any college golf scholarship opportunities that he wanted. Now, the Suis spend the winter playing amateur events throughout Florida, and Justin could possibly turn professional next fall.

“My dad keeps me calm and tells me jokes,” Sui said. “When we get to the ball, we talk about situation. He keeps me company, keeps nerves down.”

Sui’s finish had to share the stage with Ryan Nicholson’s low round. The 2024 Nease High School graduate shot a 9-under-par 62 that included seven birdies and an eagle and established a new tournament and course 18-hole record. Nicholson, 18, is taking a gap year before moving on to play college golf at Kennesaw State next fall.

The tournament is scheduled again for December 5-7, 2025.