One shot back at seven under are Justin Thomas (14), Marc Leishman (10), Brendan Steele (10), Hideki Matsuyama (9), Xander Schauffele (7) and Rickie Fowler (6).
The 2009 British Open victor made his first appearance at the U.S. Open in three years, having secured a qualifying spot at the Columbus, Ohio, sectional.
Harman closed with two birdies and three tough pars for a 5-under 67 that gave him a one-shot lead at 12-under 204.
"I did everything I could to make more birdies coming in", he said.
Thomas finished in style, and it had nothing to do with his hot pink trousers.
On the final hole, a 667-yard par 5, Thomas hit a 3 wood (!) off the tee that travelled some 350 yards, leaving himself 310 yards to the pin, with a slight following wind.
"I'd like to shoot a good round here, you know, I'm on the verge of it I feel like", Stricker said.
Zach Johnson holed an 8-foot putt on the par-3 ninth for his third birdie of the front nine.
Thomas leads the U.S. Open after shooting a 63 in the third round, matching the major record for low score.
"The finish was awesome".
It is the 31st time a 63 has been recorded at the four big dances, with Greg Norman and Vijay Singh the only golfers to do it twice. "It means I have a lot better chance to win the tournament than I did when the day started".
"A little disappointing to end with the double on 17 but I started hitting it a lot better on the back side", Hadwin said minutes after his round.
"I think since my dad dropped me off at football practice and told me to not be disappointed if I didn't get to play at all", Harman said, drawing laughs. With a blind shot to the green, he went long into deeper hay, and his first hack at it moved the ball only a few feet.
Thomas set the U.S. Open scoring record despite registering a pair of bogeys, offsetting them with nine birdies and his closing eagle.
Thomas was tied for 24th at two under par, five strokes off the pace after Friday's second round. He was 10 under.
"It's going to be a really cool day for someone tomorrow", Fowler said.
"I was upset with the score I had made, but it did not have any effect on my attitude or how I was going to then approach the rest of the round or the next shot. When I get it going, I don't fear it like I used to of stalling".
Fleetwood and South Korea's Si Woo Kim are the only non-Americans in the top 13.
Johnson shot 1-over 73 on Friday to finish at 4 over, three shots off the cut line.
Provided the rain stays away, Brandt Snedeker believes the course will get dry and fast enough to create a little more separation. He's only two shots behind Champ, still with a chance of joining Crenshaw, Leonard and Spieth as Longhorn U.S. Open low-am medalists. Thomas rolled in an 18-footer that went right to left from the edge of the green.
The USGA has a history of pushing the envelope when setting up courses for the USA championship.
"So, I am a pretty happy man".
But the work is not done. "It will be a pleasure to go out on a Sunday trying to win a major".
Theresa May pledges £5M for Grenfell Tower victims
May on Friday announced a 5 million pound ($6.4 million) fund following meeting with survivors of the Grenfell Tower tragedy. The Prime Minister also said there had been "huge frustrations" on the ground as people struggled to find information.
Grenfell Tower fire: Protests as anger grows
They are fully aware of the true scale of this tragedy but can not comprehend why they are not being given more information. Experts estimate they could have been added at a cost of £200,000 during the £10m building works.
Cavaliers season ends with Game 5 loss to Warriors
Lue makes a valid point, as his team played well in games 3-5 in the series. "They assembled a great team", James said. At the very least, the near-win gave Cleveland some life. "I think I answered that I wouldn't go.
Amir fit for Champions Trophy final
India , however, does have an upper hand since Pakistan usually is on the losing side against India in ICC tournaments. The 2017 Champions Trophy for them has been a sort of similar tale.