MAMARONECK, N.Y. — Matthew Wolff might be too young to realize he's supposed to hit fairways to have a chance to win the U.S. Open. Or maybe he's so good it doesn't matter.

Wolff hit only two fairways Saturday and still matched the lowest score ever at Winged Foot in a major, a 5-under 65 that gave the 21-year-old Californian a two-shot lead over Bryson DeChambeau going into the final round.

Whether it was the first cut or the nasty rough, Wolff kept giving those hips one last swivel before blasting away and giving himself birdie chances. He made enough of them to seize control, and then let so many others crumble.

Patrick Reed, tied for the lead at the turn, couldn't find the fairway and paid dearly with a 43 on the back nine. Reed had a three-shot lead after two holes. He walked off the 18th green with a 77 and was eight shots behind.

Collin Morikawa won the PGA Championship last month in his first try at age 23. Wolff is playing his first U.S. Open at age 21. Is he next?

“I’m probably going to be a little antsy. It’s the U.S. Open, and I have a lead,” Wolff said. “I’m going to try to keep my nerves as calm as they can be. I put myself in a really good spot. I did everything that I could do up until this point, and tomorrow I’m going to go out there, I promise you I’m going to try my best.”

He was at 5-under 205. Not since Francis Ouimet in 1913 — also the last time the U.S. Open was played in September — has a player won the U.S. Open in his debut.

DeChambeau could easily have gone the same route as Reed, missing left and right, gouging his way out of the grass. But after opening with two bogeys, he kept scrambling away — 15 straight holes with nothing worse than par. He rallied with two late birdies until missing a short par putt on the 18th for a 70.

He will be in the final group for the first time in a major, another quiet affair with no spectators on the course.

The U.S. Open began with 21 players under par. There were six going into the weekend. Now it's down to three, with Louis Oosthuizen efficiently putting together a 68 to finish at 1-under 209.

Hideki Matsuyama (70), Xander Schauffele (70) and Harris English (72) were at even-par 210. Another shot back was Rory McIlroy, who posed his 68 some three hours before the leaders finished.

“It doesn't take much around here ... and all of a sudden you're right in the thick of things," McIlroy said. “No matter where I am at the end of the day, I feel like I've got a pretty good shot.”

It all depends on Wolff, an NCAA champion at Oklahoma State who won on the PGA Tour in his third event as a pro last summer in the 3M Open in Minnesota.

From the first cut of rough on the opening hole, he hit it to right level of the contoured green for a 15-foot birdie. From the right rough on No. 4, he wound up with another 15-foot birdie putt. And then he really poured it on.

He drove next to the green on the short par-4 sixth, getting up-and-down from a bunker for birdie. He holed a 12-foot birdie on the par-3 seventh. And when he finally hit his first fairway on No. 8, he missed a 6-foot birdie attempt.

His lone bogey came on the 16th when he was in such a bad lie in the rough he couldn't reach the green. And he finished with a most fortuitous hop. His iron off the tee hopped into the thick rough and back out to the first cut. He ripped 7-iron to 10 feet for one last birdie.

“If I don't hit fairways tomorrow, I know I can play well,” Wolff said with a smile. “Even when I was in the rough, I had a bunch of good numbers and a bunch of good lies.”

And he played a lot of good golf, so good that even at his age, he looked to be a daunting figure to catch.

“I don't think there's any ‘chasing’ out here,” Schauffele said, adding that if Wolff had another good round Sunday it would be “impossible to catch him.”

DeChambeau gave himself hope, among five players within five of the lead on a course where anything goes. Think back to the last U.S. Open at Winged Foot in 2006, when Geoff Ogilvy hit a superb pitch to 6 feet for par that he thought was only good for second place until Phil Mickelson and Colin Montgomerie closed with double bogeys.

“I feel like I'm ready to win out here and win a major,” Wolff said. “It is a major. It's really important and yes, it is really early in my career. But I feel like I have the game to win. Collin won at 23. I'm 21. And I'm not saying that it's going to happen. But I put myself in a really good spot, and obviously I’m feeling really good with my game.”