Tiger Woods made his best start to a US Open for a decade on Thursday, but for defending champion Rory McIlroy and world number one Luke Donald - and some other big guns - it was a round to forget.
Woods, his confidence back after victory in the Memorial tournament two weeks ago, posted a one-under-par 69 at the Olympic Club in San Francisco.
It put him in joint second place and part of a group which also included Justin Rose and 2010 winner Graeme McDowell.
They were three strokes behind surprise leader Michael Thompson, a qualifier who was runner-up in the US Amateur on the course five years ago.
McIlroy, an eight-shot winner a year ago, struggled to a 77, however, and Donald, his search for a first major looking set to go on, managed only a 79.
Lee Westwood was paired with them and after a double bogey start he battled back for a far more respectable 73.
But Phil Mickelson lost a ball up a tree with his opening drive and signed for a 76 - his joint worst start in 22 US Opens - and Masters champion Bubba Watson - the other member of the star morning group alongside Woods - fared even worse with a 78.
As for China's 14-year-old Andy Zhang, the youngest player ever to compete in the event and called up only on Monday when England's Paul Casey pulled out injured, he began triple bogey, double bogey and needed a birdie on the last just to break 80. At least he could say he matched Donald.
The shot of the day came from American Nick Watney. Two months after Louis Oosthuizen's albatross in The Masters Watney had one with a 190-yard five-iron at the long 17th. It was only the third in US Open history and he was another in on 69.
Woods said: "I played well - I felt like I had control of my game all day and stuck to my game plan.
"We knew it (the course) was going to be quick, but we didn't think it was going to happen overnight.
"I was really, really surprised how much it changed - it was just like they used sub-air on the whole place and you had to make adjustments.
"I was very pleased with every fact of my game and I stayed very patient."
Mickelson said: "I didn't play very well obviously. It was a tough day playing the way I did and three-putting the fourth really hurt.
"I've got a tough challenge just to get to the weekend. I will see if I can shoot under par - maybe that will get me there.
"Tiger struck it really well. He had real solid control of his flight and trajectory."
For most of the day Woods, who has not added to his 14 majors since the third of his US Open victories four years ago, was supremely impressive on one of the toughest lay-outs in golf.
Missing the green on the 419-yard 14th - his sixth - was his first mistake and after bogeying there he came back with a two-putt birdie at the 522-yard 17th.
The opening six-hole stretch is the one that really sorts the men from the boys - just ask Zhang - but Woods sank curling birdie putts of nine and 30 feet at the fourth and fifth.
He described the second of those as "a fluke - that putt was off the green".
It might have been better. He missed from barely four feet at the second, but then came another bogey after he found sand on the sixth.
Mickelson, five times a runner-up, began last year by hitting his first shot into water and this time he had to take the long walk back to the tee after his hooked drive was lost high up in the branches somewhere.
Although he made birdie with his second ball, it was the start of three successive bogeys - and more were to follow.
Watson's second shot from the rough moved only a few yards and by the time he double-bogeyed the 344-yard 18th - his 10th of the day - he was already five over.
"The course beat me up today," he said. "It's a lot better than I am - it beat me by eight.
"It's disappointing and it doesn't matter what tournament it is."
Thompson, a 27-year-old from Alabama with only one top-10 finish all year on the PGA Tour, was two over after six, but then birdied the seventh and ninth and in a blistering back-nine 32 picked up more shots on the 11th, 12th, 14th and last, where he pitched to seven feet.
Rose finished with birdies at the seventh and eighth and McDowell birdied the 17th and 18th to complete a fine day's work.
Scot Marc Warren - playing in his first major at the age of 31 - kicked off with a birdie on the 449-yard ninth, but in the end had to be content with a 73.
Dubliner Padraig Harrington had two four-putts and a three-putt in his 74, while England's Robert Rock and Matthew Baldwin, like Warren a major rookie and qualifier at Walton Heath two weeks ago, shot 75 and 74 respectively.
McIlroy said: "It's just so tough here if you put yourself out of position at all. Too many times I just was in the wrong position off the tee or with my second shot.
"When you're trying to play catch-up on this golf course it's very hard. I was able to make one birdie - I need to try to make more tomorrow and limit the mistakes.
"But you have to be so precise. Anything just a little off and it really punishes you.
"I tried to approach it like any other tournament I play and tried to go out there and shoot the best score I could.
"It wasn't my greatest day, but hopefully I can come out tomorrow morning and try and shoot a good one and at least try to be here for the weekend."
Collated first round scores (USA unless stated, par 70):
66 Michael Thompson
69 Nick Watney, Tiger Woods, Justin Rose (Eng), Graeme McDowell (NIrl), David Toms
70 Robert Karlsson (Swe), Jim Furyk, Alistair Presnell (Aus), Beau Hossler, Ian Poulter (Eng), Matt Kuchar, J B Park (Kor), Jason Bohn
71 Francesco Molinari (Ita), Martin Flores, Casey Wittenberg, Branden Grace (Rsa), John Peterson, Ryo Ishikawa (Jpn), Michael Allen, Jonathan Byrd
72 Anders Hansen (Den), Robert Garrigus, Blake Adams, Charles Howell III, Webb Simpson, Rickie Fowler, Jason Dufner, John Senden (Aus), Nicolas Colsaerts (Bel), Angel Cabrera (Arg), Raphael Jacquelin (Fra), Alberto Sanchez, D.A. Points, Hunter Mahan, Aaron Watkins, Fredrik Jacobson (Swe), Morgan Hoffmann
73 Charl Schwartzel (Rsa), Kyle Stanley, Steve Le Brun, Davis Love III, Joe Ogilvie, Garcia Sergio (Spa), Keegan Bradley, Marc Warren (Sco), K J Choi (Kor), James Hahn, Jeff Curl, Lee Westwood (Eng)
74 Spencer Levin, Gary Woodland, Martin Kaymer (Ger), Peter Lawrie (Irl), Simon Dyson (Eng), Bob Estes, Rafael Cabrera Bello (Spa), Jordan Spieth, Nicholas Thompson, Y.E. Yang (Kor), Stephen Ames (Can), Rodney Pampling (Aus), Tim Herron, K.t. Kim (Kor), Matthew Baldwin (Eng), Kevin Chappell, Kevin Na, Charlie Wi (Kor), Casey Martin, Gregory Bourdy (Fra), Padraig Harrington (Irl), Tommy Biershenk
75 Justin Hicks, Mikko Ilonen (Fin), Colt Knost, Jesse Mueller, Paul Claxton, Vijay Singh (Fij), Robert Rock (Eng), Alexander Noren (Swe), Ernie Els (Rsa), Roberto Castro, Retief Goosen (Rsa), Darron Stiles, Scott Piercy, Hiroyuki Fujita (Jpn), Alvaro Quiros (Spa), Jason Day (Aus), Dustin Johnson, Aaron Baddeley (Aus), Carl Pettersson (Swe)
76 Matteo Manassero (Ita), Anthony Summers (Aus), Geoff Ogilvy (Aus), Patrick Cantlay, Matt Bettencourt, Edward Loar, Samuel Osborne (Eng), Scott Langley, Bill Haas, Steve Stricker, Adam Scott (Aus), Lucas Glover, Brendan Jones (Aus), Mark Wilson, Kevin Streelman, Phil Mickelson
77 Cameron Wilson, Tadahiro Takayama (Jpn), Zach Johnson, Louis Oosthuizen (Rsa), Brian Harman, Stewart Cink, Brooks Koepka, Ben Crane, Rory McIlroy (NIrl), Sang-moon Bae (Kor), Martin Laird (Sco), Hunter Hamrick, Olin Browne, Brian Gaffney, Dong-Hwan Lee (Jpn), Tim Clark (Rsa)
78 Tim Weinhart, Scott Smith (Aus), Bubba Watson, George Coetzee (Rsa), Alex Cejka (Ger), Toru Taniguchi (Jpn), Peter Hanson (Swe), Joe Durant, Thomas Bjorn (Den), David Mathis, Bo Van Pelt, Brice Garnett, Jim Herman, Nick Sherwood, Shane Bertsch
79 Michael Campbell (Nzl), Andy Zhang (Chn), Luke Donald (Eng), Lee Slattery (Eng)
80 Trevor Immelman (Rsa), Dennis Miller, Cole Howard, Gonzalo Fernandez-Castano (Spa), Chez Reavie
81 William Lunde, Miguel Angel Jimenez (Spa), Hunter Haas
82 Kyle Thompson, Mark Mccormick
84 Steve Marino
85 Soren Kjeldsen (Den), Brian Rowell
