Fog briefly delayed Thursday morning's early start at the 3M Open, a befitting nod to golf's Scottish roots, before a spectacularly blue and uncommonly quiet Minnesota summer's day at TPC Twin Cities revealed a rare afternoon leader.

Former Golf Channel "Big Break" winner Richy Werenski was that late clubhouse leader with an 8-under-par 63 that led 2013 Honda Classic champ Michael Thompson by a stroke and seven other players — including world 17th-ranked Tony Finau, five-time tour winner Ryan Moore and defending champion Matthew Wolff — by two.

He did so on a day when a hot putter and accurate iron play put him atop the leaderboard while world fourth-ranked Dustin Johnson withdrew citing a back injury. Stretching it often between swings, he shot a 78 that included three balls hit in the water on his ninth hole — TPC Twin Cities; par-5 18th — for what he called a "tap-in" 9.

Werenski called his season "kind of a funky year" that included a broken wrist that sidelined him last fall and then the "whole corona thing" that did the same starting in March. He tied for 17th at the Honda Classic just before the shutdown and has made the cut in all four events he played since.

3M Open leaderboard

"But the game feels really good," Werenski said after posting nine birdies and a bogey and tying his career-low round.

The seventh PGA Tour event played this summer without spectators here in the age of the coronavirus pandemic, the 3M Open proceeded without galleries and grandstands, as a made-for-TV event instead. Camera towers and hand-sanitizing stations dotted the former sod farm in Blaine as a gentle breeze carried mostly birdsong and players' praise for their opponents' shot on it. The day's starter introduced competitors on the first and 10th tees with a simple "On the tee" announcement to the relative few on the course.

So much has changed since Wolff was crowned champion in his rookie season with a winning eagle putt in the inaugural 3M Open last year, but there he was again Thursday afternoon playing himself into contention — this time on the tournament's first day with a 6-under 65.

"Playing today, I was going through my head about the memories and the shots that I hit all week last year," Wolff said. "This might have been my best first round of my career. I feel like I've usually been fighting to make that cut unless I have a really good second round. So it was just nice to go out there, shoot 6 under par and now tomorrow all I'm going to be doing is thinking about taking it deep and doing what I did today."

Finau's 65 came in his return after he played last year's 3M Open in a state where he has many cousins, aunts and uncles. He ate Wednesday night at a restaurant an uncle runs. Maybe it was good luck.

"Had a nice steak," he said. "I think I'll be there more often this week."

Moore is Pacific Northwest born and raised, but he has his own Minnesota connections. He clinched the Ryder Cup for his U.S. team at Hazeltine National Golf Club in 2016 after he was the last player named to it just seven days before. He also won the 2004 U.S. Public Links at Rush Creek.

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"I've played some good golf around here," said Moore, who missed cuts in three of his past four starts and seeks his third top-10 finish this season.

"I'm not sure why."

Moore also won the NCAA individual title and the U.S. Amateur that summer but maybe never was better than in that victory in Maple Grove.

"Weirdly enough, I remember that one pretty well," said Moore, who last won a PGA Tour event in 2016 six weeks before the Ryder Cup. "It was probably my best golf I played that summer, and I won quite a few tournaments that summer."

Moore clinched that Ryder Cup by beating Europe's Lee Westwood on the 18th green of their Sunday singles match.

"That's all a blur," Moore said. "I probably remember less of that than the Publinx, but it was an amazing week. It was a whirlwind the way it all happened, but it's something I'll remember forever."