SANDWICH, England — Oklahoma State junior Ethan Fang held off a late charge Saturday with a 5-foot birdie putt on the final hole for a 1-up victory over Gavin Tiernan of Ireland, becoming the first American in 18 years to win the British Amateur.

The match at Royal St. George’s was all square through 31 holes when Fang built a 2-up lead, Tiernan won the next two holes with big putts, and Fang won it on the 36th hole with an approach shot just 5 feet left of the hole.

Tiernan, a sophomore at East Tennessee State, missed well to the left some 45 feet away and grazed the edge of the cup with his long birdie putt, setting the stage for Fang.

Fang, who grew up near Dallas and played his freshman year at Cal, earned a trip to the British Open next month and gets into the Masters at Augusta National next year.

“Probably one of the longest days of golf I’ve ever played,” Fang said. “I just hit a really good shot on the last hole.”

The last American winner of the British Amateur was Drew Weaver in 2007 at Royal Lytham & St. Annes.

Tiernan led 1 up after the morning 18 holes, and neither player was ahead by more than one hole until late in the match. Fang two-putted for birdie on the par-5 14th, after Tiernan hit a poor pitch that left him some 30 feet short. Fang went 2 up when Tiernan got in trouble off the tee at the 15th and made bogey.

But the Irishman answered in stunning fashion — a 30-foot birdie putt to win the hole on the par-3 16th, and a 15-foot birdie putt on the 17th to square the match again.

Fang held his nerve with two great shots to set up birdie and change his summer plans. Fang was already looking good for the Walker Cup in September at Cypress Point, and this victory might be enough to seal a spot on the team for the No. 7 player in the world amateur ranking.

But first up is another test of links golf at Royal Portrush for The Open Championship.

“Playing the Masters and Open Championship is going to be sweet,” Fang said. “I had signed up for a couple of amateur tournaments (this summer), but think I’ll cancel that.”