Fourth-ranked McIlroy, who has not won a major since the 2014 PGA Championship, battled through the tricky opening holes, found birdies where he could and scrambled late to stay in contention.

“It was really good,” he said. “Key for me was to just try to play the first five holes well. To get through those in even par, I knew in that middle section you could make a couple birdies and then hang on coming in. Knocked a couple in when I could. A really good round of golf.

“You’re going to have stretches in US Opens where you’re going to make mistakes, but if you can back it up with stretches of golf like I showed there, that’s what you have to do. It’s not going to be all plain sailing in this tournament.”

Wolff, a 21-year-old American making only his second major start, fired a five-under par 65 to lead at five-under 205 after 54 holes.

The 2019 US college champion for Oklahoma State, who shared fourth at last month’s PGA Championship in his major debut, solved wicked Winged Foot to lead American Bryson DeChambeau by two shots.

“Every time I was in the rough and had a good lie I took advantage of it,” Wolff said. “I minimised the mistakes. It was a good day all around.”

South Africa’s Louis Oosthuizen, the 2010 British Open champion, fired a 68 to be four shots behind.

“Any under-par round at a US Open you’ll take,” Oosthuizen said. “(Wind) definitely died down for us. Definitely lucky on the draw today.”

World number 36 Wolff, who won his first PGA Tour title at Minneapolis in only his third tour start, needed only 10 putts over his first nine holes, shooting an astonishing 30 on the front nine as veteran rivals struggled on the famed Mamaroneck, New York, layout.

“I tried to shoot as low as possible with hitting as few fairways as possible,” Wolff joked. “That will get me ready for tomorrow.

“I got really fortunate with the lies in the rough. I just stuck with my game. We had a bunch of good lies. It was a grind out there.

“I’m just going to go out there, do the same thing and whatever happens happens.”

Japan’s Hideki Matsuyama, who made four birdies and three bogeys in his first seven holes, scrambled to a 70 to stand alongside Americans Xander Schauffele and Harris English on level par 210.

McIlroy, playing his first major since the birth of daughter Poppy, said the lack of spectators as a coronavirus safety precaution removes potential distraction for leaders as well as inspiring cheers for chasers.

“It’s one variable that you just don’t have to deal with,” McIlroy said. “Maybe not a loss of an advantage to me, but just makes it a touch easier for the guys at the top. It just makes it a little different and maybe a touch easier if you’re in those final few groups.”

McIlroy still sees plenty of trouble ahead for US Open leaders.

“It doesn’t take much around here,” he said. “Someone gets off to a decent start, maybe 1- or 2-under through five, and then the leader goes the other way, 1- or 2-over through five, and all of a sudden you’re right in the thick of things.

“I feel like I’ve got a pretty good shot.”