From Rickie's history making 65 to the World's best struggling, we recap an eventful first day at Erin Hills.
While it may have made USGA members uncomfortable watching scoring records broken and Rickie Fowler notch up seven birdies, there's no doubt that the new US Open venue also showed signs of its teeth.
Rory McIlroy's stats show that he spent more time in the fescue than on the fairway on day one, and with tougher weather conditions on the horizon and the inevitable overnight pin position changes - it won't be suprising if we have seen the last of the hoards of low scoring.
But as we anticipate the start of the second round, it seems only just to take a look back at the biggest talking points of day one...
Fowler makes history
Rickie Fowler's seven-under-par round was not just his lowest ever round in a major tournament, but the lowest round (to par) in a US Open since 1980 - where Jack Nicklaus and Tom Wieskopf shot a pair of 63s.
Fowler's opening round was without a single blemish, with four birdies on his first nine joined by more gains on his 10th, 11th and 16th holes to gain a one-shot lead over the rest of the field.
He took advantage of the calm and warm conditions, but the 28-year-old admitted he wants to go one-better than his runner up finish in 2014.
“It’s always cool to be part of some kind of history in golf,” said Fowler. “But I’d rather be remembered for something that’s done on a Sunday.
“There are a lot of really good players out here that haven’t won a major. So it would be nice to get rid of that at some point. I’m not saying that this is the week or isn’t the week but I like the way this course suits me.”
Both Masters Champion Sergio Garcia and World No. 14 Paul Casey began their rounds with eagles on the very first hole, starting the afternoon challenges strongly.
Casey made the biggest move on the leaderboard with six additional birdies including at the last - but two bogeys on his card meant he would end the day at six-under par, securing his spot in a tie for second.
"I'm delighted with 66. I've don't think I've ever started a US Open with a birdie let alone an eagle," Casey said.
"I'm feeling really really good about this golf course. This has an Open feel to it... maybe that changes the feel and maybe that's just something I've lacked at previous US Opens."
He was joined at six-under by US Open rookie Xander Schauffelle, who grabbed a spot in the tournament through a play-off during a section qualifier. The pressure of the big stage didn't seem to phase Schauffelle, who carded a bogey-free 66 that could have been two shots better if it hadn't been for two narrowly missed birdie putts on his final two holes.
Brian Harman, Brooks Koepka and England's Tommy Fleetwood lie in a share of fourth place having played in the morning conditions and all finishing with five-under 67s.
Marc Leishman and Kevin Na carded a pair of 68s to sit a further shot adrift on four-under, while Garcia finished with a birdie of his own to end up at two-under with nine others including Ernie Els and Charley Hoffman.
The most phenomenal afternoon run came from the Valspar Champion Adam Hadwin, who had six birdies in a row on his back nine (the front nine), but a three-putt dropped him back to three-under - the same score posted by Andrew 'Beef' Johnston.
Scoring record broken
The USGA are renowned for wanting to see players struggle on their courses, but we sat down with Mike Davis and he admitted it could possibly be different at Erin Hills.
But perhaps he didn't think it would be record-breaking. The US Open record for sub-par rounds during the opening round at the second major of the year was 39, in 1990. At close of play on Thursday at this year's tournament, the number stood at 44.
Big names struggle
Every single one of the World's top six players finished over-par with disappointing starts to their US Open campaigns. Both Dustin Johnson and Jordan Spieth struggled on the greens, with Spieth saying: "I hit the ball phenomenal, just didn't make anything. I missed one fairway today, which is the best driving round that I've had maybe in my life."
"I had 15 looks at birdie today and all of them were actual makeable putts and I only made one of them. Just a really off day putting, but I'll go figure it out."
Spieth finished one-over par, while World No.1 and defending champion Dustin Johnson will start the second round 10 shots behind Fowler at three-over.
Conversley, it was problems from the tee that really hurt both Jason Day and Rory McIlroy. Day carded two triple bogeys (the first time he has ever done that in his career), while McIlroy spent a lot of time in the fescue he had originally criticised the USGA for cutting back.
In total, McIlroy hit just 5 out of 13 fairways to end up six-over (which all occured on the back nine), while Day had four birdies and still left the course seven-over par and in a share of 151st place.
World No.6 and Open Champion Henrik Stenson was four over for his round, which was a very mixed bag. Although he hit one of the shots of the day with an eagle, he also had three birdies, five bogeys and a double which made for a disappointing two-over par 74.
The weather conditions were warm and windy, which meant no possible way for Phil Mickelson to make it from his daughter's graduation to his afternoon tee-time on Thursday.
As lefty missed his first major tournament since 1993, in stepped first alternate: Roberto Diaz.
It was an understandably shaky start for Diaz, who sprayed his drive in to the much discussed fescue to end up with a bogey - but he finished the day with a respectable even-par 72.
Blimp crashes and bursts in to flames
The drama was not refined to on-course during the first round of the US Open, as a commericial blimp nearby the course caught fans attention as they filmed it deflating, falling to the ground and catching fire.
A USGA statement read: "According to local authorities, a commercial blimp not affiliated with the USGA or the U.S. Open Championship broadcast crashed in an open field approximately a half mile from the Erin Hills golf course at approximately 11:15 a.m. CDT.
"First responders were quick to arrive at the scene and the pilot is currently being treated for unknown injuries. No other people were involved in the incident and local law enforcement is currently investigating. Our thoughts and prayers are with the pilot at this time."
The best shots of day one
There were a few wonderful shots on day one, and none more so than the eagles recorded by Hideki Matsuyama, Paul Casey and Rory McIlroy (before his run of back-nine bogeys).
Prior to that, there was numerous birdies throughout the morning's play - and the USGA was kind enough to put them in to little highlight videos for us below.
The Eagles. . .
The birdies . . .