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.
"Not every day you enjoy a round of golf with an 8 on the card, but I'm a pretty happy man", Casey told the tournament's website. "I felt like I've been playing pretty well all week, and didn't have quite the numbers to show for it".
"I birdied the first two holes, but those were tap-ins".
"Guess what?" he said to his 4-year-old son. "It's just like I said, you've got to keep it in the short grass, out of that fescue, and don't make any bogeys". Even just trying to take my medicine is very, very hard.
Two rounds down and two to go at the US Open at Erin Hills and we are still no closer to discovering the identity of the 2017 US Open champion.
"That fifth shot at 18 was my best shot of the day", Fleetwood said. And I think with everything so large, your target is larger and your misses get even more extreme. "There were a couple of dicey pin placements out there that you had to be careful about, but it was still scoreable".
Also at 5 under was Si Woo Kim (70), Xander Schauffele (73), amateur Cameron Champ (69) and Brandt Snedeker (69).
Rickie Fowler (-6) - Fowler quickly climbed to 9 under, and looked like he might really make life hard for the rest of the field, but three straight bogeys on his back nine derailed all momentum. One of many in the mix trying to win their first major championship, Casey will have to limit mistakes over the weekend, and continue finding fairways. "And I've been very light on competitive rounds this year, and it's just a matter of getting into a good round of golf now".
Fowler goes into the third round knowing he got away with having something less than his best stuff on Friday, but he's just 1 shot off the lead after 36 holes.
"This week I've been working with my coach, just sitting there and thinking, all right, let's go out and try to make a good golf swing and try to make a good putt". McIlroy expressed fondness for Erin Hills despite heading home early.
"Usually when you shoot even in a U.S. Open and you're one off the lead, you're not six down afterward", J.B. Holmes said.
"But I still think things are going to toughen up".
"I'd like to shoot a good round here, you know, I'm on the verge of it I feel like", Stricker said.
He added another birdie on the par-3 13th.
"I'm optimistic with where my game is ... some of where my game is". Fellow-countryman Graeme McDowell follows him out of the tournament, joined by the likes of Jason Dufner, Jason Day and Danny Willett - who withdrew due to the recurrence of a back injury.
The last time Day missed a cut in a major was the 2012 PGA Championship, ending a run of 17, which was the longest active streak.