OAKMONT, Pa. — Trailing on the back nine at Oakmont for the first time all week, Austin Greaser responded by winning four straight holes and closing out Travis Vick on the 17th hole in their semifinal match Saturday in the U.S. Amateur.

Greaser has yet to play the 18th hole in match play in five rounds.

Next up is the 36-hole championship match against Michigan State senior James Piot, who also made a big run around the turn in a 4-and-3 victory over Nick Gabrelcik.

The perks already began pouring in for the finalists, who earn exemptions to the Masters in April and the U.S. Open at The Country Club in June. The winner Sunday also earns a spot in the 150th British Open at St. Andrews.

They all knew what was at stake, along with the size of the gallery, with close to 1,000 people following along in the fairway and on the edges of the green.

Greaser, who won the Ohio Amateur last year and is going into his junior season at North Carolina, felt more nerves than ever against Vick, who three times took a 1-up lead.

And then Greaser seized control, starting with a conventional play down the 11th fairway — some players have been going left toward the 10th fairway for a better angle to the pin — and hitting wedge to 8 feet. He hit another pitch to 8 feet below the hole on the par-5 12th.

Vick couldn’t keep up, and dropped another shot with on the par-3 13th by going from a bunker to the rough. Greaser saved his best for the end of that big run, hitting driver that carried some 320 yards onto the green for a two-putt birdie from 35 feet.

“Best drive I hit all week,” Greaser said.

Vick tried to keep it close, winning the 15th with a par when Greaser hit two poor shots, and the par-3 16th when Greaser couldn’t save par from a bunker.

But on the reachable 17th, Vick pulled his drive into foot-long hay that was laying over. He couldn’t get that to the green, chipped 15 feet long, missed the par putt and conceded.

None of the last nine holes were halved.

“It stings when there’s something to play for, like the Masters, and you show up and don’t play your best golf,” Vick said.

Piot was scrappy as ever, having grown up on a public course complex in Michigan where it was not unusual to for him to play 72 holes in a day.

He dropped only two shots at Oakmont — the first hole that has given him fits all week, and the par-3 eighth with a soft chip from just over the green. Otherwise, he kept it in play off the tee and kept stress at a minimum, leaving he mistakes to Grabelcik.

The match was all square through eight holes when Grabelcik got in trouble off the tee at No. 9 and made double bogey. Grabelcik gave another hole away on the 10th with a long three-putt bogey, and Piot holed a 25-foot birdie putt on the 11th to start putting away.

The clincher came at the 15th, when Piot found a bunker off the tee and had to lay up short of the green. He hit his third into 15 feet and holed the par putt, while Grabelcik went into a greenside bunker and couldn’t save par.

The 36-hole championship match means Greaser, the No. 82 player in the world amateur ranking, will play the 18th hole for the first time since qualifying. Piot, a fifth-year senior because of the COVID-19 pandemic, is No. 86 in the amateur ranking.