SOUTHAMPTON, N.Y. — The U.S. Open suits Tommy Fleetwood, particularly when conditions get difficult.

You know, wind and rain and chilly temperatures, just like back home in England. Exactly like Fleetwood got on Friday morning at Shinnecock Hills.

Fleetwood posted the best round of the morning at 4-under-66. He did it during the worst weather of the day.

He trailed leader Dustin Johnson by five shots because Fleetwood opened with a 75, and first-round co-leader Johnson nearly matched Fleetwood's 66 with a 67.

"I do quite like it in sort of a funny way," Fleetwood said. "But I don't know. I like to think I can control my ball well, but I still feel like I'm getting a lot better at it. And I think that some of the strengths I have, I have a lot of patience ... the tougher the conditions, the more I feel like I can grind it out and will my way around a little bit.

"You still got to play well, but all those go together in a good round if everything still applies. If you play bad, I still feel like I can keep it together and keep going. Whether I shoot 10 over or 66 today, I feel like, when the weather is bad, I kind of have that in me, the mental side."

That's a critical asset on a course such as Shinnecock, with its myriad challenges even before the elements are added in. Some of the world's best players — Tiger Woods, Jon Rahm, Rory McIlroy and Sergio Garcia, for example — appear to have let frustration get in their way so far. Fleetwood easily could have done so on Thursday when he bogeyed four of five holes in one stretch.

Instead, he showed the grit it takes to be on the leaderboard at a major.

"No matter what I did, the ball just did the opposite of what I was trying to, pretty much, and I couldn't get it in the hole in the back nine," he said of the opening round. "It just shows then I was 6 over through 15 yesterday, three holes still left to play. And I think, especially at a U.S. Open, you have to keep your head down. You have to keep going.

"I made a bunch of bogeys on that back nine in a row, made one birdie in the last three, and then get a round like today and you're back in it."

Fleetwood's first season as a PGA Tour member — he joined the European Tour in 2011 — has been going pretty well. He's missed one cut in 10 events, finished fourth at both the Honda and team event in New Orleans (partnered with Chris Paisley), and tied for seventh at The Players Championship.

His four pro victories all have some on the European PGA circuit, including the Abu Dhabi Championship last year and this.

Shinnecock Hills is his third U.S. Open course. He tied for 27th at Chambers Bay in 2015, then wound up fourth in 2017 at Erin Hills, shooting 11 under to winner Brooks Koepka's 16 under.

Clearly, while respectful, Fleetwood isn't intimidated by this tournament.

"I do like the setup of a U.S. Open," the 27-year-old said. "It is the ultimate test of golf in more ways than one. It tests your long game, short game, every aspect. It tests you mentally, physically. If you're going to win a U.S. Open, which is one of the biggest events in the world, it should be that kind of test.

"And ... nobody had played it like it did yesterday in practice. So whatever you practice and you know it's tough, it was nothing like yesterday. It was a completely different golf course. So I don't think anybody was like fully prepared for that."

Asked if he is fully prepared to challenge Johnson, the world's No. 1 player, at the top of the leaderboard, Fleetwood didn't seem ready to place a bet on it. He wasn't backing off, either.

"I know Dustin's going well, so I might be a few shots out of full contention," Fleetwood said. "But I'm all of a sudden in a position where I can have a good round tomorrow and be up there for Sunday, hopefully."