Rickie Fowler produced a sparkling 65 on Thursday to take a one shot lead into the second round of the 2017 US Open Championship.
The two-time European Tour winner fired seven birdies and no bogeys on Thursday morning to equal the record for the lowest score in relation to par in the first round of a US Open.
Afternoon starters Paul Casey and Xander Schauffele were in a share of second on six under after posting matching rounds of 66 at Erin Hills.
Brian Harman, Brooks Koepka and Englishman Tommy Fleetwood were another shot back on five under.
World Number Nine Fowler, starting at the tenth tee, made the most of favourable scoring conditions in the morning, firing back-to-back birdies at the 11th and 12th before rolling in his 12 foot birdie putt at the 14th to get to three under.
He then made three consecutive birdies at the 18th, first and second to take the outright lead before rolling in his ten foot putt for another at the seventh to get to seven under.
After his round, Fowler said: "It is always cool to be part of some sort of history in golf. But I'd rather be remembered for something that's done on Sunday.
"I like the way this golf course suits me, and we're off to a good start. There's definitely a lot of golf to be played.
"It was nice. You don't get many rounds at the US Open that are stress-free.
"I just did a good job, knew I needed to drive it well and from there I was just able to manage hitting and continuing to swing well and hitting good shots and rolling a couple in.
"So, simple day when you look back on it, and how we kind of pieced our way around the golf course - it's a lot easier said than done."
Casey made a dream start to his first round, chipping in for an eagle at the first before carding a birdie at the second to get to three under.
He dropped his first shot of the day at the fourth but bounced back with a gain at the sixth before adding another at the ninth.
After carding a bogey at the tenth, he picked up further shots at the 11th and 15th before rolling in from four feet for a birdie at the last to get to six under and become the first person to get within one shot of early clubhouse leader Fowler.
Casey said: "I watched Rickie this morning. I love watching the golf in the early morning at Major Championships, and this morning was no exception.
"I'm a Rickie Fowler fan, and the golf he proposed this morning was beautiful.
"I was hoping and praying if I could get the same kind of conditions and hoping and praying I would be half as good as Rickie Fowler, so to be right behind him, I'm ecstatic.
"I've never started off with an eagle before at a US Open Championship. I really enjoyed it. Great crowds - I love the whole experience."
American Schauffele, starting at the tenth tee, reached the turn in 34 after making two gains on his front nine.
He made further birdies at the second, fourth, fifth and seventh to join Casey on six under.
And he had a great chance to join Fowler at the top of the leaderboard at the ninth - his last - but he narrowly missed his 15 foot birdie putt.
Schauffele said: "I'm a rookie and this is my first time here. I'm sure I'll hear people say 'let's see if he can keep it up', or 'he's got game'. Both sides of it.
"I'll try to be me and hopefully that will be good enough."
