But only for a couple minutes.
Four others are within three shots as the third round winds down. He just didn't know how much history.
Paul Casey is the latest example of how little it takes to record a big number in the U.S. Open.
And at this U.S. Open, he showed how a quick recovery is never too far away.
And then Friday, a 94-year-old man at the tournament for the first time stopped breathing while in a grandstand on the sixth hole and died of what Washington County officials said appeared to be natural causes. The top 18 players on the leaderboard going into the weekend have combined for zero majors. It was 1 over at Medinah in 1990.
Don't try this at home.
It didn't work all that well. He two-putted for birdie, and he rolled in a 25-foot birdie putt on the 17th.
Erin Hills also played like a beast.
"Guess what?" he said to his 4-year-old son. Casey is tied with Rickie Fowler at 7 under for the lead.
Another U.S. Open first for Xander Schauffele.
Hoffman birdied five of his first eight holes to get to 9 under, one shot clear of a massive logjam in second. They were joined by Harman and Fleetwood, who each had a 70. His best finish was a tie for 37th a year ago at Oakmont.
The world number 14 found himself in trouble when he flew his approach out of rough over the green into the deep fescue and needed five more strokes to get in the cup.
Casey, Koepka, Harman and Fleetwood have yet to tee off. He shot a 69 and was at 2-under 214.
Another warm, dry day is drying out the course during the second round of the U.S. Open, and the players are noticing a difference.
Hideki Matsuyama had quite a day at Erin Hills. He just has to listen to the crowd.
Reavie is playing in his fifth Open, but first since 2012 at The Olympic Club in San Francisco. However, he then birdied 17 through to the third and parred out the remainder of his round for a 71 and two round total of 137.
Not bad for someone who had to claim one of the 14 qualifying spots at the tough Columbus, Ohio, sectional last week to make it to Wisconsin.
The 21-year-old Kim is charging up the leaderboard in the second round of the U.S. Open.
A commercial blimp crashed to the ground and caught fire just outside the course Thursday, about the time the county health department was analyzing samples that confirmed evidence of the E. coli bacteria in water at a hydration station near the 12th hole. Newly branded as the "ultimate test in golf", the U.S. Open has always been famed for its toughness and Erin Hills was expected to add to that hard-man reputation.
Brooks Koepka started on No. 10 and made four birdies on his front nine to get to 9 under, moving into a tie with Fowler for the top spot. If Johnson's opening round was disappointing, Day's 79 was disastrous.
Low scores were available.
The pace might actually pick up when the PGA Tour veteran leaves Erin Hills. Jordan Spieth was even par through 12 holes and going nowhere. He's twice been sidelined this year due to a rib injury, and had played just the Players Championship since the Masters.
Schauffele double bogeyed the par-3 13th hole. He made an 8, and followed that with a tee shot into the rough to make a bogey. "It's kind of tough to prepare because there's three or four tee boxes on nearly every hole that we could be playing from".
The U.S. Open is wide open going into the weekend.
Fowler, sharing a house with Thomas this week, was being left behind until he ran off three straight birdies and shot 68.
There were 18 rounds in the 60s, starting with one for the record book.
But that's not all that makes the possibilities so limitless Saturday. He shot 73 and missed the cut by three. The top 60 and ties qualify for the final 36 holes.