Unheralded Americans Justin Hicks and Kevin Streelman upstaged tournament favourites Tiger Woods and Phil Mickelson by taking charge in Thursday's first round at the US Open.
Nationwide Tour player Hicks, helped by a run of six birdies in eight holes, fired a three-under-par 68 to set the early pace before being joined by PGA Tour rookie Streelman late in the day.
World number one Woods, who had not previously walked 18 holes since having knee surgery two months ago, carded a topsy-turvy 72 while playing partner Mickelson returned a 71.
Australia's Geoff Ogilvy, the 2006 champion at Winged Foot, opened with a 69 to share third place with compatriot Stuart Appleby and Americans Rocco Mediate and Eric Axley.
Hicks, a journeyman from the minor tours competing in only his second US Open, piled up seven birdies and four bogeys on the ultra-long South Course at Torrey Pines.
"For me, it's a great round," the 33-year-old told reporters. "It's a US Open and I've never been able to say that I've been under par at a US Open before.
"I know that it's a marathon, not a sprint, and our goal is to keep playing good, steady golf and try to be standing here on Sunday night."
Streelman, 18 days after getting married, joined Hicks atop the leaderboard with a mix of six birdies and three bogeys.
"It probably hasn't quite sunk in yet, but it's pretty cool," said the 29-year-old, who tied for 29th at the Buick Invitational at Torrey Pines in late January. "I do enjoy this golf course. The lines off the tee kind of suit my eye well."
Woods, who had arthroscopic surgery on his knee two days after finishing second at the Masters in mid-April, was satisfied to end the first round just four strokes off the pace despite feeling pain in his knee late in the day.
UGLY START
"You couldn't ask for a worse start than I got, six on the very first hole out of the gate," the 13-times major champion said after a round featuring three birdies and two double-bogeys.
"I figured you're going to make bogeys out here, I just happened to make two on the very first hole.
"I wanted to get to even par as fast as I could and then try and get to under par for the day," added Woods, who was grouped in a dream trio with world number two Mickelson and third-ranked Adam Scott of Australia.
"And I did that. I got to under par at the turn and just didn't keep it there. To make two double-bogeys and a three-putt and only be four back, that's a great position to be in.
"I hit the ball pretty good all day, had a couple of misses left, but just need to clean up the round just a little bit."
After making a nightmare start in overcast conditions, Woods recovered to birdie the fourth, eighth and par-five ninth, where he struck a delicate lob wedge from tangly rough to four feet.
Out in one-under 34, he made several par-saving putts from around 15 feet on the back nine but marred his round by running up another double-bogey at the par-four 14th.
Watched by huge galleries and a media contingent of around 100, three-times major winner Mickelson birdied the last for a 71 while Scott, nursing a broken bone in his right hand, returned a 73.
"It was not the best round," said Mickelson. "I made a couple mistakes early on, but the back nine I made some birdies.
"Anything around par is kind of your target for the US Open and I should have a chance tomorrow to try to keep it around par, maybe get a couple birdies here or there."