OAKMONT, Pa. — Sometimes it helps not knowing what could go wrong.

Having never played a competitive round at Oakmont Country Club before, J.J. Spaun proceeded Thursday to chart his way around one of the toughest U.S Open tests in just 66 strokes and finished the opening round with a 1-shot lead at 4 under.

He was the only player without a bogey or worse on Day 1.

“I kind of came out here with no prior history at Oakmont, not really knowing what to expect, even U.S. Open-wise. This is only my second one,” Spaun said. “I don’t know if that freed me up in any aspect, but I just tried to kind of take what the course gave me.”

Spaun became the first player with a bogey-free round at Oakmont since Dustin Johnson’s first round in 2016. Johnson, of course, went on to win his first major championship and finished the tournament at 5 under.

Over his 18 holes in Thursday’s opening round, Spaun hit eight of 14 fairways and 12 of 18 greens in regulation. But where most of his scoring came on his first nine (he teed off on the 10th hole) with four birdies in his first eight holes for a record score of 31, what he did on his second nine was perhaps more impressive, as he scrambled for par and never had a three-putt on Oakmont’s treacherous greens.

“It’s challenging in every sort of aspect or variable in golf,” Spaun said of Oakmont. “You’re obviously going to have to grind when you’re out of position, and I did that really well today.”

Spaun’s putter was incandescent during the first round. The 34-year-old made 90 feet of putts and gained nearly four strokes on the field with his putter alone.

“I think today was one of my best putting days I’ve had maybe all year, especially inside like the makeable range putts, inside 12 feet or so,” Spaun said. “I like converting those putts, because that’s huge for momentum and keeping a round going, and that’s kind of what happens here at U.S. Opens.”

The last time Spaun, who is ranked 25th in the world, was in the spotlight was three months ago at the Players Championship, where he went toe-to-toe with Rory McIlroy in a three-hole Monday playoff but could not take down the five-time major winner.

With five top-15 finishes this season, Spaun has been playing well overall, but he is coming off a missed cut at the Memorial. It’s safe to say no one expected him to stitch together a round such as the one he did Thursday.

“I was actually pretty nervous. But I actually tried to harness that, the nerves, the anxiety, because it kind of heightens my focus, makes me swing better,” Spaun said. “I like feeling uncomfortable. I ended up feeling pretty comfortable towards the end of the day, but there’s a long way to go.”

Even being in contention at a Players is nothing like what Spaun will experience now that he has put himself in prime position at a major championship on a golf course that will get only harder, and the pressure will only grow.

Both he and his competitors know it.

“It’s Thursday,” Xander Schauffele, who birdied the last two holes to shoot 2 over, said. “I just told J.J., ‘Incredible round, nice playing. Good luck the rest of the way.'”