It put him at 10 under, three out of the lead, and Fowler never got closer.
"Yeah, first cut made, too (at the U.S. Open)", Harman said.
Thomas, decked out in shocking fluorescent pink trousers, produced a no less electric performance signing for nine-under 63 to equal the lowest numerical score in a major and the best ever in the 117 year-history of the US Open in relation to par.
He tied for 13th in last year's Open at Oakmont.
Jordan Spieth's first attempt to get out of the bunker on the 18th hole Saturday ended badly.
But Thomas is no stranger to records.
That put him in Sunday's final pairing - a 2:54 p.m. tee time - and Thomas, an early bird, said it was "bizarre for me", hanging around the house he shared with Fowler, trying to avoid the phone, the TV, all that was being written and said about him until it was time to go to the course. "I'd love to have another one of those", Thomas said.
Thomas, however, is not alone in that pursuit. But now has the U.S. Open champion he knows that he chose the right career.
US Open 2017: Four tied for lead heading into the weekend
Even as the course slowly recovered from rain early in the week, reasonable scores were available. Wisconsin made the cut on the number. "I've never played in [one of the final pairings of] a U.S.
South Korea's Kim Si-Woo was one behind Fowler on nine under after also shooting 68, while three players - Patrick Reed, Russell Henley and Charley Hoffman were on eight under.
"It was a great day", said Fowler, who is still gunning for his first major title.
He rolled in an 18-foot birdie putt on No. 5 from the edge of the green that broke so severely that he stood with his toes facing the hole and rapped the ball toward his left foot. He most likely held the win at -14, but displayed his strong mind by increasingly closing the gap as he got closer to the finish line, with a final score of -16. I was thinking if you can get 4 or 5-under par today, it would be a pretty good score to get yourself in the golf tournament. "It could change in a heartbeat".
Thomas said he has enjoyed playing at the first-ever US Open in Wisconsin.
"I mean there's probably not that much that's that interesting to be honest", he smiled. "But you can't do anything about that stuff".
Although things got awkward when they mistakenly identified his girlfriend as his old one and told the wrong story. On Saturday, he followed five birdies on the first nine with three bogeys on the back and on Sunday there was a triple bogey No. 8 sent him free-falling down the leaderboard.
They fearlessly attacked the pins and nobody was more ruthless than Thomas, who ripped apart the links-style layout carding nine birdies and two bogeys before capping his record-smashing effort by coolly rolling in an eight-foot putt for eagle at the par-five 18th.
He started the final round one shot back of Harman but birdied the first two holes to take the lead. I think it's a fair course. I thought I played pretty solid on Tuesday. The scores are low, but we're playing well. Justin did it today. "But, at the same time, I don't feel like I lost a golf tournament, I think Brooks went out and won the tournament". "That's a very real possibility". He lives in Sea Island, Georgia with his wife and daughter. "(There's) no reason to answer that", said Thomas, who is now ranked 13th in the world.
Li turned professional at age 16 and won the Volvo China Open last year on the European Tour, securing a two-year membership and qualifying for the Rio Olympics.