He had a chance to match Jonny Miller's U.S. Open record for low round in relation to par, but he settled for par on the 676-yard 18th.
Johnson was hitting it so well that he appeared to be safe even when he was on the cut line. "Just excited to get on a run of golf and get going". He missed the 15-footer. Starting on the back nine, he exchanged a birdie on 11 with a bogey on 12.
This is the longest course on tour this year, but if the 50-year-old can manage to keep it in the fairways, he's got an opportunity to pick up some strokes on the golfers now ahead of him.
It was the first time Day has missed the cut in seven U.S. Opens. It was 1 over at Medinah in 1990. It'll require supreme power and precision, players who don't have it will quickly fall by the wayside.
Rickie Fowler has some company on top of the U.S. Open leaderboard.
Zach Johnson holed an 8-foot putt on the par-3 ninth for his third birdie of the front nine.
Casey had an action-packed second round. No other information was provided. The Northern Irishman then won the Open Championship and US PGA in 2014, meaning he needs only to win the Masters to become the sixth player to complete a career grand slam.
It sounds as if Erin Hills is becoming more challenging with each passing minute.
McIlroy, as well as Day, will play the Travelers Championship near Hartford, Conn., next week as he gears up for the British Open. "It sets up really well for me, especially if I'm driving it like I did today", he said. "If the sun stays like it is and the wind keeps baking this golf course out, it's pretty treacherous on the weekend, which is just what I would like, and I think what the rest of the players want to see".
Harris English is 4 under after a second-round 69.
In the final round at Oakmont a year ago, his golf ball moved slightly as he positioned himself for a short putt on the fifth hole.
English says "They want par to be a good score, and this afternoon it will be".
Sure, he birdied four of his last six holes to salvage a 71 and finish at 5-over 149. He grabbed his putter and pointed it out to his left just as the ball dropped into the cup. His total of 154 equaled his worse two-round total at a major, matching his first two rounds at The Open in 2013. This one he'd rather forget.
He added another birdie on the par-3 13th. Later, a long put for bogey rolled just right of the hole before he tapped in. Casey is the odd-man out of that group with a 71 on Friday, but the end result still has him in excellent position heading into the weekend.
Amateur Scottie Scheffler is playing with the poise of a veteran at the U.S. Open. He tapped in for par. Fowler is also in search of his first major title. The Englishman shot a 1-under 71, but had to fight back from two bogeys and a triple bogey in his first six holes. Hadwin's shotmaking improved the back nine, that's when the putter cooled off.
Casey discovered how little it takes to make a big number in the U.S. Open - and at this U.S. Open, how a recovery is never too far away.
The U.S. Open is wide open going into the weekend.
The performance of the 23-year-old from San Diego has been no less remarkable.
Now, he's still very much in play, at six under after shooting a 73. "You never know what one shot's going to count for".
Matsuyama spearheads an Asian challenge which also includes South Korea's Kim Si-Woo, who is also at five under. Twenty-eight holes without a bogey, followed by three consecutive.
"I lost a bit of skin out there", Casey said of the triple bogey. But that wasn't the problem.
But Casey rebounded with five straight birdies at Nos. It didn't get any better when he made the green.
"I played well enough to be contention at Erin Hills, let alone make the cut and it's disappointing". He shot 73 and missed the cut by three.
Dustin Johnson, Rory McIlroy and Jason Day made the wrong kind of history at the U.S. Open. "Every time you have a hard golf course, they'll jump out at the beginning, and Rickie (Fowler) had that great run yesterday, and he's seeing 7 (under par)".
Eight of the top 12 in the world will not be around for the weekend at this most unusual U.S. Open, where the top 60 and ties advanced to the final two rounds. There no longer is a 10-shot rule that would allow anyone within 10 shots of the lead to make the cut.