Germany's Martin Kaymer shot a stunning five-under 65 to take a three-shot lead on day one of the US Open at Pinehurst.
The former world number one, 29, hit three birdies in his last five holes to race past Northern Ireland's Graeme McDowell, Americans Kevin Na and Fran Quinn and Zimbabwe's Brendon de Jonge.
Rory McIlroy shot 71 alongside English amateur Matthew Fitzpatrick, while six-time runner-up Phil Mickelson took 70.
Defending champion Justin Rose carded 72 and world number one Adam Scott 73.
Kaymer, who won the 2010 US PGA, showed imperious form to eclipse the 68s of McDowell and Na set in softer, more receptive morning conditions on the revamped Pinehurst No.2 course.
The European Ryder Cup winner, who clinched the prestigious Players Championship last month after a spell in the doldrums trying to remodel his swing, went out in one-under 34 and picked up a further shot at the 10th before his spectacular finish on a sultry afternoon in North Carolina.
"It's nice if you have just won before," Kaymer said. "I needed it for my confidence, for all the work I put in the last couple years, to show it was all worth it. I see things very positively right now."
McDowell, the 2010 US Open champion, eagled the 528-yard par-five fifth alongside one bogey and one birdie and said his mental preparation had been spot on.
"Perhaps it wasn't my most amazing ball-striking round, but this golf course you don't have to stripe it, you just have to hit in the correct places as often as you can and then you've just got to grind and pace putt as well as you can and make as many pars as you can," the 34-year-old, who was also second in 2012, told BBC Sport.
"This golf course is going to get firmer and faster just got to stay ultra patient and ultra conservative."
Countryman and playing partner McIlroy, the winner in 2011, leaked bogeys at the sixth and seventh before making amends with a birdie on the ninth to go out in 36.
A further dropped shot came at the 16th before he birdied the last.
"I stayed patient and got rewarded with a birdie at 18," McIlroy said. "It was a grind out there at times but to shoot plus-one was a solid day.
"I just have to work on my speeds on the greens. Content? Definitely. I'm only three off the lead and it's only going to get firmer."
Open champion Mickelson dropped two shots in his last four holes to slip back as he bids to win the US Open for the first time to complete the career Grand Slam of all four majors titles.
Mickelson, who turns 44 on Monday, would join Jack Nicklaus, Tiger Woods, Ben Hogan, Gary Player and Gene Sarazen in clinching all four majors with victory this week.
"If I can manage my game and play it smart and just focus on the shot at hand, I feel like I'll give myself a good chance," said Mickelson, who was second behind Rose at Merion last year.
The 19-year-old Fitzpatrick, the US amateur champion, had a share of the lead at two under but dropped three shots in his last five holes, playing alongside Rose and Mickelson.
"That was great, I really enjoyed it," said Fitzpatrick, who turns pro at the Irish Open next week. "They are both great guys and both really supportive if I hit a good shot."
The 33-year-old Rose, looking to become the first player since Curtis Strange in 1989 to make a successful title defence, said: "I drove the ball really well. Putting felt comfortable. My short game was very poor."
Sweden's Henrik Stenson, who could leapfrog Scott in the rankings with victory on Sunday, ended one under alongside Masters runner-up Jordan Spieth, 20, fellow Americans Matt Kuchar, Brandt Snedeker, Dustin Johnson, Harris English, Keegan Bradley and Brendon Todd, Japan's Hideki Matsuyama and Italy's Francesco Molinari.
England's Ian Poulter, Paul Casey and Danny Willett and Wales' Jamie Donaldson also finished level par alongside American Rickie Fowler, who was wearing plus fours in tribute to the traditional outfit of the late Payne Stewart, who won the US Open at Pinehurst in 1999 but died in a plane crash four months later.
Lee Westwood and Darren Clarke both ended five over, Masters champion Bubba Watson was six over and former world number one Luke Donald finished on seven over.