Defending champion Johnson out of US Open

"Taking nothing away from 9-under par - 9-under is incredible with U.S. Open pressure", Miller told GolfChannel.com.

Greg Norman and Vijay Singh are the only golfers to record two rounds of 63 in the majors. This is the first time in 25 years that the U.S. Open has played as a par 72.

The player who stunned everyone was joint-leader Casey, who got a triple-bogey on the par-five 14th hole, and roared back into contention with five consecutive birdies.

"Very cool! Very Wisconsin", a fan said.

McIlroy entered the U.S. Open having not competed since last month's Players. He said that his 16 years of experience is what allowed him to keep the wheels from falling off on the par-5 14th hole.

The round was littered with some awesome approach shots and long putts as Thomas took advantage of overnight rains to move to 11-under, one shot off the lead by Brian Harman.

Fowler, the world number nine from California, revelled in benign conditions at Erin Hills Golf Course to reel off seven birdies and 11 pars in a superb 65. He was 10 under, only two shots behind. Day, however, said he felt ready to go before flaming out early.

"I couldn't have shot any higher", Johnson said. "I'd like to shoot a good round here. But I'm looking forward to getting the job done".

If his hot pink trousers were not enough, Thomas finished in style. Koepka had the outright lead with four holes left in his round before a bogey on the par-3 sixth hole. "Oh gosh, Jimmy, be good", he said to caddie Jimmy Johnson when the ball was in the air, and it was close to flawless.

"The finish was awesome".

A classy 67 lifted the left-hander to 12 under for the week, one clear of Thomas, Brooks Koepka and Tommy Fleetwood.

He might need one at this rate.

His 7-under 65 matched Rickie Fowler and Hideki Matsuyama for the low score in the first two rounds at Erin Hills. Regardless of the weather, it didn't take long for the 24-year-old Thomas to understand the significance of his record round. If I can make four birdies around here, that would be pretty good.

"I've shown what can happen with one bad swing". Day, who welcomed adverse conditions and a hard golf course, fought off a two-way miss and couldn't make putts we're used to seeing him hole.

The Kentucky native became the youngest player to shoot 50 on the US PGA Tour during the first round of his Sony Open victory in January.

Louis Oosthuizen is making the biggest move the morning in the U.S. Open at Erin Hills. Players noticed firmer greens that were allowing putts to race past the hole. Frankly, with a slightly better putting stroke on 15, Thomas might have had two eagles and catapulted himself into the lead - but, hey, let's not get greedy. The next one went long, he chipped up to 12 feet and took two putts from there.

"The biggest thing about this course is that the fairways are massive", he said.

"Guess what? We get to go home today because Daddy played poorly", Day said to his son, Dash, before walking over to sign autographs.

But the work is not done.

Johnson, ranked No. 1 in the world, missed the cut after a 1-over 73, which came a day after he shot 75. The top 18 players on the leaderboard going into the weekend have combined for zero majors.

And become the seventh consecutive first-time major victor.

Paul Casey has a share of the lead heading into the third round. Mickelson has won every major but the U.S. Open. "So we're breaking down all kinds of barriers".