Look no further than Rory McIlroy, the No. 2 player in the world, who didn't hit a fairway after the 10th hole, shot 42 on the back nine and posted a 78, his worst score in 27 rounds at the U.S. Open.
And the former Ryder Cup player then made it five birdies in succession - just one short of the US Open record equalled by Adam Hadwin on Thursday - by picking up shots on the first, second and third.
McIlroy at least improved his position in round two, nearly holing his tee shot at his final hole - the par-three ninth - as he completed a 71 with four late birdies.
A low-scoring opening two rounds at the Erin Hills Golf Course in rural Wisconsin drew to a close on Friday with England's Paul Casey and Tommy Fleetwood in a tie with Brooks Koepka and Brian Harman on seven under par at the top.
Day never had a chance, following his career-worst 79 in a U.S. Open with a 75.
Needing a four-foot par putt to preserve par, Spieth missed and settled for bogey, which put him just one shot above the projected cut line of one-over.
World number one Dustin Johnson said he plans to take some time off with his family as he struggles to digest his US Open flop.
The top three players in the world have never missed the cut in the same major dating to when the world ranking began in 1986.
One behind first-round leader Rickie Fowler overnight, Casey birdied the 11th, his second hole, on Friday but looked to have tumbled out of contention when bogeys at 12 and 15 came either side of a dismal eight on the par-five 14th.
"I saw some positives there on the back nine coming in and hopefully I can take them to the Travelers (tournament) next week", he said. He shot 73 and missed the cut by three.
The up-and-down round ended with the Englishman signing for one-under 71 and walking into the clubhouse level with Fowler, who had yet to start his round.
"I had been swinging it well and it felt really, really good a couple holes later to be picking the ball out of the hole for a birdie".
McIlroy's performance might not be that surprising given that he's played only six PGA Tour events this year and missed most of the last month with a rib injury.
"I'm ecstatic", said the 39-year-old afterwards.
Newly branded as the "ultimate test in golf", the U.S. Open has always been famed for its toughness and Erin Hills was expected to add to that hard-man reputation. Unlikely as it seems, that was the last major he played on the weekend. The golf course is actually really handsome. "The putter was hot on the front side to keep me in it, so it's all there, it's just a matter of putting it together and I'm not out of it". "But when you're visually looking down the fairway, I think when you're trying to aim at a target at a normal golf course, with normal width fairways, there's some pressure into hitting the fairway because it is a lot narrower than we have out here".