A “completely different golf course” was how defending champion Jordan Spieth described the change in the conditions from the hard and fast, skating rink of the practice days to the rain-sodden monster that still took its share of victims.
“I mean, night and day,” added Spieth, who is four over par and five behind clubhouse leader Scottie Scheffler, the 19-year old amateur qualifier who posted a one under 69.
While Graeme McDowell was part of the afternoon wave that didn’t get to start, it fell to Shane Lowry to light up Ireland’s challenge at level par with seven holes to go as Rory McIlroy struggled to find any consistency and mixed one birdie with five bogeys to be four over after 13 holes.
With overnight storms dumping more than an inch of rain on Oakmont’s rolling fairways and slick greens, another 0.3 inches led to a second delay and the loss of four hours in total before a final deluge, followed by a crack of lightning that took out the internet in the media centre, forced officials to abandon play for the day just before 4pm local time.
While Scheffler leads on one under, Texan Andrew Landry, a 28-year old Web,com Tour graduate, is poised to set the pace as he stands over a 10 footer for a birdie at the ninth for a four under 66.
Bubba Watson (14 holes) and New Zealander Danny Lee (13 holes) are tied for second on two under with Scheffler (69), Kevin Streelman (16 holes), Lee Westwood (13) and Harris English (12) all locked together in fourth on one under.
The good news for Irish golf fans was that Lowry was in an eight-man log-jam for eighth place on level par and left with a 25 footer for birdie at the 12th when play was called for the day.
“It’s unbelievable the difference,” Lowry said of the change in conditions after a round that began with a chip in birdie from 66 yards at the first.
“There still aren't too many guys under par. I think if you hit it in the fairway, you could hit greens easier. They’re not as firm and as fast so it's definitely made it easier for us.
"Obviously the rough is a lot juicier so you really need to keep the ball in the short stuff. It's been an interesting day so far. Happy that they’ve called it and we get to go back and have a little rest and get back out there tomorrow morning
"I'm happy to hang on. I’m on even par through 11 holes and I’ve got a 25-footer on 12 for birdie, so I just can’t wait to get back out there.
"The forecast is great for the rest of the week, which is great. And hopefully, we get the second round done by early Saturday morning and get everybody in the third round Saturday afternoon.”
While some players managed to shelter in the media dining room during the first weather delay, Lowry had to wait in a hut near the seventh and like the rest of the field, he didn’t get to warm up.
“We were standing there for like well over an hour and it wasn’t ideal, but I went back out there, I felt okay,” he said. “I kind of normally don't need to warm up that much, which is good for me, but imagine some of the older guys were might have been feeling it.
"That was fine. That’s what the USGA had to do to get as much golf as they could in today.”
McIlroy was part of a marquee group playing just in front of Lowry that disappointed badly with Masters champion Danny Willett on four over and world No 5 Rickie Fowler tied 56th of the 78 players in the first wave on six over.
In fact, Willett was one of the more vocal critics of the USGA for not allowing the players to warm up after the first delay.
“No, that was a bad one,” he said. “We sat in a cabin for an hour and 10 minutes behind the seventh tee without being given a chance to hit any balls or do anything.
“It’s not like you are playing a Sunday medal, you're in a US Open, they don't give you a chance to even hit a few balls.”
If McIlroy, Willett and Fowler disappointed, Lowry was solid and at times, impressive.
The big Offaly man drove into sand at the first but his nerves were immediately eased when he splashed out to the fairway and then holed his third from 66 yards for an unlikely birdie three.
He was smiling as he walked down the fairway and smiling again when he saved par with a sensational chip and putt at the second after his approach had spun back off the front of the green
When he came back out after the first delay, he failed to get up and down from 60 yards for par at the seventh and then missed a five footer for par at the ninth to turn in one over par.
But he birdied the 11th from 15 feet and was left with a 25 footer up the green for birdie at the 12th when play was called for the day.
If Lowry was happy, McIlroy looked far from content as he hit just five of 10 fairways and mixed a lone birdie at the fourth with bogeys at the second, third, seventh, 12th and 13th.
Electing to hit a driving iron off the tee at the first three holes, he missed all three fairways and found bunkers at the second and third, dropping shots at both to go two over.
While he birdied the fourth, he was off with his distance control at the seventh, taking three from the back fringe after an overcautious chip.
Having missed a five footer for birdie at the fifth, he missed another chance from around eight feet at the 11th and then bogeyed the par-five12th.
A hook tee shot found deep rough and after hacking out, he then carved his three wood approach from 260 yards well right into more rough before missing a slick 15 footer for par.
As for defending champion Spieth, he too found the delays tough to take, especially not getting to warm up again after the first one of more than an hour.
“It was a challenge not being able to warm up too, going out there and trying to hit tee shots at the US Open, but it is what it is,” he said
“Hopefully, we'll get some good conditions in the morning, and those other guys have to play 36 holes in a row at a US Open, which isn't easy.”