Matsuyama, a 25-year-old, four-time PGA Tour victor from Japan, had a putt for birdie on the par-5 18th hole, which would have been only the second 8-under round in U.S. Open history, matching Johnny Miller's 63 at par-71 Oakmont in 1973.
Thomas, the 24-year-old from Kentucky who is a major away from joining the young elite in golf, only added to a year of low numbers.
He might need one at this rate. "For the most part, the wind was nonexistent". "I enjoyed the walk, the golf course is attractive but I just didn't execute".
In the 116 previous U.S. Opens, only six players had ever reached 10-under par or better, never in the same tournament. And none of them was particularly close on a first-time major championship layout that has played soft.
Thomas fired nine birdies and an eagle on the 18th to card a nine-under-par 63 and take over the clubhouse lead on 11 under par, two shots clear of compatriots Brian Harman and Brendan Steele and England's Tommy Fleetwood. But a 675-yard par-5, nobody's hitting to that.
"I wasn't thinking too much about 8 under", he said through an interpreter.
Rickie Fowler failed to capitalize on the great conditions, shooting a 73 that kept him on the first page of the leaderboard but left him in a three-way tie for second place with Jamie Lovemark and JB Holmes.More news: Brooks Koepka wins US Open, ties Rory McIlroy's scoring mark
Hideki Matsuyama and Chez Reavie both shot the rounds of the day, posting seven-under 65s to move to five and four under respectively.
"I really haven't been hitting the ball well as of late", Matsuyama said. "But at least I'll get to sit in air con [conditioning] and watch the guys tear it up on the weekend". But his stay was short-lived, giving the stroke right back with a bogey at the next hole followed by a triple bogey at par-five 14th. "I feel like that's going to help me to get back into contention and hopefully try to win some of these things".
That was a 10-shot improvement on his second round and left the 26-year-old on eight under par as he seeks to turn his Ryder Cup heroics into individual success.
Still to be determined was who made it to the weekend, and where the cut would fall.
There were 68 players who made the cut at 145, 1 over par. For the second straight year, Rory McIlroy is packing his bags early, as is defending champion Dustin Johnson and world No. 3 Jason Day. It is the first time since the introduction of the official world rankings in 1986 that the top 3 players in the world missed the cut in the same major championship.
"You can not play this golf course if you're not in position off the tee and I wasn't in position", McIlroy said. As we all know, this game is all about putting. "It's pretty simple, (we) just didn't get it in the hole fast enough". "And I'm kind of going out there and just doing it, and letting it go". But I don't let it bother me. I'll probably just play for sure to get ready for the British. The forecast calls for overnight showers and scattered thunderstorms throughout Saturday. And then he came up short of the 17th green and dropped one more shot that sent him home early to spend time with his newborn son.
It sounds as if Erin Hills is becoming more challenging with each passing minute.