That increased the likelihood of a seventh successive major producing a first-time victor, although the likes of Masters champion Sergio Garcia and Martin Kaymer - who claimed U.S. Open glory in 2014 - were handily placed four off the pace.
"Tomorrow will be a very cool experience", Fleetwood said.
"If you look at the golf course and you talk to me, Jason or Rory, this course sets up flawless for us".
The soft, forgiving conditions created opportunity for major movement up the leaderboard for those players willing to take it.
Behind the leading quartet, a logjam grouped eight players within two shots of the lead.
On a crowded leaderboard, American amateur Cameron Champ - who turned 22 on Thursday - and Xander Schauffele were unlikely contenders on five under par alongside Matsuyama, Players Championship victor Si Woo Kim and Brandt Snedeker. "But I'm a pretty happy man". "There were a couple of dicey pin placements out there that you had to be careful about, but it was still scoreable".
Stricker improved by a stroke even though Erin Hills showed a few more teeth than it had in Thursday's opening round.
"It will be just fine", said Fowler, who plays in the third-to-last group on Saturday. Among those trying to chase him down is Paul Casey of England, who was one shot behind.
Casey laid up in the rough, took two chops to get out of more rough behind the 14th green, and staggered away with a triple-bogey 8 that might have ruined his day at Erin Hills. He made four birdies over the last six holes to salvage a 71, but at 5 over, he missed the cut for the second straight year. Garcia carded an eagle, three birdies and three bogeys in a roller coaster round.
Rory McIlroy and Jason Day also left Erin Hills earlier than anyone expected.
Day, the world number three, shot a 3-over-par 75 on day two to be 10-over and he will be joined on the sidelines by Scott, after the 2013 Masters champion finished on 3-over courtesy of a 75 in the second round. It's there that the mistake was made: Hadwin tried to play too ideal of a third shot up toward the raised putting surface.
Eight of the top 12 players in the world won't be around for the weekend at Erin Hills, leaving a tournament as open as the land on which it was built.
McIlroy however, who is returning from a hip and back injury, put a fearless face on his second consecutive missed cut at a US Open following his exit at the halfway stage in 2016. "I enjoyed the walk", he said.
"I couldn't possibly shoot any higher than I did", Johnson said. It's just a matter of getting competitive rounds under my belt. It was wonderful to see that there was, I felt, no knee-jerk reaction to yesterday's scores.
And with the tees moved up on the 15th hole to make it reachable, Thomas hit a 3-wood that rolled off the back slope of the green to 6 feet.