In the group ahead leader Brooks Koepka didn't slip up.
Koepka, whose caddie Ricky Elliott is from Portrush in Northern Ireland, becomes the seventh first-time major victor in succession, a run stretching back to Jason Day's victory in the 2015 US PGA Championship.
A ideal tee-shot left him in the centre of the fairway and he then ripped his second some 300 yards to leave himself with an eight-foot putt to clinch the lowest to par score in the history of the US Open.
Spieth had five birdies and two bogeys in a final round that was particularly impressive given the rising winds at Erin Hills.
"What I've done this week is unbelievable", Koepka.
China's Li Haotong dropped four shots in his opening four holes, with a double-bogey and two bogeys.
The 27-year-old Koepka grabbed control with three straight birdies on the back nine at Erin Hills.
Whether this has been a good US open so far seems to be in the eye of the beholder. Let's take a look at who has the best chance of winning the 117th U.S. Open.
And now he gets to keep it for a year, with his name on it. He proved such a trembling mess that he birdied No. 14, birdied No. 15, birdied No. 16 and sprinted from the others.
Harman, bidding to become the first left-hander to win a US Open, is a victor on the PGA Tour this year and he leads in Wisconsin by a stroke, with world number 13 Thomas, Brooks Koepka and England's Tommy Fleetwood (both 68) sharing second place.
Harman, who had begun the day in a four-way tie for the lead, carded a five-under-par 67 which included six birdies and one bogey. Matsuyama didn't need to stick around very long.
"Good job", his wife, Kelly, said as she greeted her husband with a kiss. "Obviously, Brooks dealt with it amazingly".
He had a pretty good final round, too, shooting a 3-under 69 to finish at 5 under for the tournament. "Now he's done it in a major". His nine-under finish pushed him to 11 under for the championship.
Just about everything already has at Erin Hills.
Li, 21, turned professional at age 16 and won the Volvo China Open last year on the European Tour, securing a 2-year membership and qualifying for the Rio Olympics. But the low scoring went much deeper than that.
Erin Hills, with wide fairways that are unprecedented for a U.S. Open, has allowed players to mash drivers like Mike Trout.
KEY STATISTIC: In 116 U.S. Opens to date, only six players had ever reached 10 under or better. What slowed him on Saturday was a triple bogey on the third hole, but conditions were so tough that Woods shot even-par 71 and still increased his lead to 10 shots.
But is he playing well enough to win a U.S. Open?
Thomas' 3-wood from 299 yards banked into the front of the green and trickled purposely towards the pin on the 18th hole at the U.S. Open.
Day never had a chance, following his career-worst 79 in a U.S. Open with a 75. The strongest gusts were Sunday morning and it tapered to a strong breeze by the afternoon.
"There are so many great ones to choose from".
There was one last ovation as he walked off the 18th green after putting for par.