Such low scoring might suggest the 11-year-old course was a cream puff, hardly the USGA's idea of the ultimate test in golf.
Just don't mention that to some of the best players in the world.
And Day was even worse off, a 75 leaving him tied for 150th.
Si Woo Kim, who captured The Players Championship a month ago, had a 70 and was at 5-under 139 along with a pair of US Open newcomers. "If we can't hit it within that avenue, you might as well pack your bags and go home".
Jason Day has given himself the green light to go on a birdie blitz on day two of the US Open after his second-worst score at the majors. When you're trying to aim at a target usually at a normal golf course, with normal width fairways, there's some pressure in hitting the fairway.
World number one Dustin Johnson was facing a battle of his own to make the cut. Look for one of them to make a few birdies and hop up the leaderboard and into contention.
And then, Fowler took a bogeys at Nos.
For now, fans continue to cheer on the best golf players in the world during the historic U.S. Open for Wisconsin.
"You don't get many rounds at the U.S. Open that are stress-free", Fowler said. "But I'd rather be remembered for something that's done on Sunday".
Just like that, Casey is 4 over for the day and now five shots out of the lead.
With Johnson, McIlroy and Day misfiring, it was left to a clutch of unheralded players to dominate the upper reaches of the leaderboard.
However, of the leading 18 not one has tasted success in a Major and, in fact, you have to look down to those sharing 19 place before singling out a Major Champion and they are reigning Masters victor Sergio Garcia (71) and double Major winning Martin Kaymer (69) at three under.
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.
"We're happy to be here, you have great golf, great weather; what more could you want", said a spectator.
McIlroy bounced back with a birdie from 12 feet on the 13th, but carded a hat-trick of bogeys from the first to slump to nine over par.
Umbrellas at Erin Hills will have a different objective given the rainy forecast for Saturday.
The pilot of the craft, who was the only person on board at the time, jumped out before hitting the ground, according to police. "But I think definitely getting a lot speedier, a lot faster".
That's when he made a birdie at the par-5 18th hole. He was 100 feet away for birdie on No. 6 and burned the edge of the cup on that one, except that it ran by some 7 feet and he three-putted for bogey.