ERIN, Wisconsin - Erin Hills made its debut as a US Open course on Thursday with a most gracious welcome for Rickie Fowler, who matched the record to par in the opening round with a 7-under 65 on the longest course in major championship history.

Fowler's flying start gave him a one-shot lead over Paul Casey and tournament newcomer Xander Schauffele.

And they had plenty of company in red numbers, so much so that Erin Hills set a US Open record for the first round by yielding 44 sub-par rounds, breaking by five the record set in 1990 at Medinah.

Such low scoring might suggest the 11-year-old course was playing too easy, hardly the USGA's idea of the ultimate test in golf.

Just don't mention that to some of the best players in the world.

Jason Day had two triple bogeys and posted a 79, his worst score ever in the US Open.

"I just played bad golf, man," Day said.

Rory McIlroy joked earlier in the week that anyone who couldn't hit such wide fairways "might as well pack your bags and go home". He spent all day in the knee-high fescue and shot 78, his worst US Open score.

"You cannot play this golf course if you're not in position off the tee, and I wasn't in position," McIlroy said. "Obviously, I paid the price for it today."

Defending champion Dustin Johnson probably didn't feel so badly by the end of a most peculiar day. He only shot 75, with just one birdie.

"You won't get a better day for scoring," Johnson said wistfully during the long walk to sign his card.

No one took advantage like Fowler.

Fowler, who shared the 36-hole lead at the Masters in April, never came seriously close to bogey because he was never in trouble. He kept it in the short grass, the secret to Erin Hills that wouldn't appear to be that difficult because of the wide fairways.

"You don't get many rounds at the US Open that are stress-free," said Fowler.

The 28-year-old's seven birdies were from no more than 12 feet, including three in a row around the turn. His 7-under round tied the record to par for a Thursday of a US Open held by Jack Nicklaus and Tom Weiskopf, who each shot 7-under 63s at Baltusrol in 1980.

"It is always cool to be part of some sort of history in golf," said Fowler, who has never won a major. "But I'd rather be remembered for something that's done on Sunday."

Day and McIlroy, just to name a few, might not make it that far.

Most bizarre about this day was that as many amateurs broke par as top 10 players in the world - two apiece.

Masters champion Sergio Garcia (No 7) shot a 70. Fowler is at No 9 in the rankings. Scottie Scheffler, who just finished his junior year at Texas, had a 69 and amateur Cameron Champ fired a 70 in his US Open debut.

For players like Jordan Spieth (73) and Johnson, it was a matter of not making enough putts. For most others, like Henrik Stenson, it was being careless off the tee and facing the rigorous test of recovering.

Casey started eagle-birdie and finished with two birdies over the final four holes for his 66.

"I was just trying to have half as good a round as Rickie had," said Casey, who played in the afternoon. "The scoring was so good this morning. I was happy it stayed benign for us, and I capitalized on it."

Schauffele had a chance to tie Fowler for the lead until his 12-foot birdie putt on the par-3 ninth slid by on the right.

The opening round was without Phil Mickelson for the first time since 1993. The 46-year-old was in California for his daughter's high-school graduation, hopeful for enough of a weather delay to jet across the country to Wisconsin. But as the sun rose over Erin Hills, and the forecast was for no rain, Mickelson withdrew.

More startling than the low scores was smoke rising from about a half-mile away when a commercial blimp crashed into a field and burst into flames. The pilot, the only person on board, was being treated for injuries.

Associated Press

Rickie Fowler and his girlfriend, pole vaulter Allison Stokke, stroll off the course after Fowler fired a first-round 65 to lead the US Open on Thursday.Rick Wood/journalsentinel Via Usa Today Sports