He made the eagle to get his name in the record book. The next one went long, he chipped up to 12 feet and took two putts from there.
Thomas is the 31st golfer to shoot a 63 at a major. But a trip into the fescue grass after a wayward tee shot cost the Australian a double-bogey and he ended tied-17 at four-under par, probably out of the hunt with a round to play.
Even Thomas, who is at 11-under 205, one shot back, conceded that the usual uncomfortableness of the U.S. Open has been lacking this week.
Rickie Fowler, who is two shots back, said after his round Saturday that he was hoping the wind would pick up to make the course tougher.
"I just get a little shaky and jittery on putts, and that's what happened on 15, " he said.
"Oh gosh, Jimmy, be good", he said to caddie Jimmy Johnson when the ball was in the air, and it was close to ideal.
"It's been an off-week for me with the putting", said the former world number one.
"It was a really good round of golf and you don't realise until you start talking about it that I hardly missed a shot all day".
"When I saw it was about seven feet away I knew maybe we had a chance of history". Kubly, whose company has built or renovated scores of world-class golf courses (including U.S. Open hosts Southern Hills and Torrey Pines) and whose daughter remembers trips to visit with pros-turned-course designers such as Arnold Palmer, Nick Faldo and Jack Nicklaus, has experience in that area.
The 27-year-old Koepka grabbed control with three straight birdies on the back nine at Erin Hills. But I'm just so excited to give myself a great chance to win this golf tournament.
"It was definitely conducive for good scores today. I said, 'Boy, a golf course has to be built here.' Just in the same way that I did the first time that I set foot in the Sand Hills out here in Nebraska". The bogey there put him at 2 over, and on the par-5 14th, he overcooked a chip shot up the steep hill, which led to another three-putt and another bogey.
Harman might be the surprise leader after three rounds at the U.S. Open, but there was nothing ordinary about his game.
"It doesn't matter how long, how whatever the course is", Thomas said about the longest course in major championship history.
"(The wind is) going to blow and the scores could be a good deal higher tomorrow if the weather comes to what they're predicting", Harman said. I was just happy that I was the one that was able to take advantage of it today. "It will be a pleasure to go out on a Sunday trying to win a major". A lot of them had to come from far back going into the weekend, and it was hard to put together two good rounds.
"It's going to be a really cool day for someone tomorrow", Fowler said.
Then again, none of the top 16 on the leaderboard has ever won a major.