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. Only Louis Oosthuizen, Zach Johnson and Sergio García realistically have the prospect of another major win from here, with even that trio's chances highly remote.
Around 70 minutes earlier, compatriot Patrick Reed had faced a similar length putt to Thomas on the 18th to shoot eight under but missed his birdie attempt and had to settle for a 65.
"It was never that way in the U.S. Open".
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. "I'm not sure when it's going to sink in".
"But more important than that was just to get myself in contention to win the tournament". Tomorrow's going to be fun.
"I think this is the best I've ever felt at a US Open; definitely the most comfortable I've felt on a US Open course".
Thomas eagled his final hole to shoot the lowest single-round score in relation to par in U.S. Open history.
The 24-year-old American fired the lowest score relative to par in the 117-year history of the championship, his nine-under round eclipsing Johnny Miller's eight-under 64 at the 1973 US Open at Oakmont. He said he'll play a lot and work on his putting in advance of the British Open at Royal Birkdale next month.
Thomas produced a 59 at the Sony Open in January. "But I've enjoyed this experience". "Struck it well, had a couple putts that could have gone that didn't, but had a bunch of looks, hit a bunch of greens, and that's what you've got to do to play well around here".
He was at 8 under at the end of the day, and never got back to double digits.
Still to be determined is what kind of test Erin Hills can present the rest of the week, especially with more rain on the way Friday and Saturday afternoon.
His purple patch has instilled the belief he's ready to become the seventh consecutive first-time major victor, a run started by Jason Day at the 2015 US PGA Championship.
With the likes of Dustin Johnson, Rory McIlroy, Jason Day and Jordan Spieth missing the cut at the U.S. Open, the final two rounds of the major from Erin Hills looked like it would be a boring affair.
McIlroy won the US Open with a record 16-under-par total in 2011 and claimed his second major title in the US PGA the following year. But he missed a pair of 10-foot birdie chances in that stretch, and one of the birdies he made was a two-putt from 20 feet on the par-5 seventh. And he missed an eminently makeable eagle putt after driving the green on the par-four 15th.
It's not much different than what USGA executive director Mike Davis said about bringing the U.S. Open to Erin Hills, a course that only opened 11 years ago.
"Struck it well, hit a bunch of greens, and that's what you've got to do to play well around here".