Michael Thompson used his experience at The Olympic Club to his advantage on Thursday as he carded a four-under 66 to take a three-shot lead after the first round of the 112th U.S. Open.

Thompson, who was the U.S. Amateur runner-up at Olympic Club in 2007, arrived last Friday to get plenty of practice, especially around the greens.

And did it ever pay off.

He needed just 22 putts in his first round, which was just the seventh round he ever played in a major championship, and first as a professional.

Three-time champion Tiger Woods carded three birdies and two bogeys in a round of one-under 69. The last time he opened with a score in red figures at this championship was in 2002 on the Black Course at Bethpage. Two of the three times he won this title, Woods opened with an under-par score.

Woods shares second place with former PGA Champion David Toms, Justin Rose, 2010 champion Graeme McDowell and Nick Watney, who had a double-eagle on the par-five 17th on Thursday.

Amateur Beau Hossler carded an even-par 72 in the opening round. He was joined in seventh place by Ian Poulter, Matt Kuchar, 2003 champion Jim Furyk and four others.

While Woods shot 69, his playing partners -- Phil Mickelson and Bubba Watson -- struggled in round one. That trio started on No. 9 as players are starting on the first and ninth this week, instead of the normal first and 10th tees.

Mickelson lost his opening tee shot on No. 9. He never recovered from the opening bogey as he went on to shoot a 76, which matched his worst first-round score at U.S. Open. He also shot 76 in round one in 1996 at Oakland Hills.

"I didn't play very well, obviously. You could see that," Mickelson said. "I fought hard there for a while trying to keep it a few over. But it was a tough day when you play it the way I did."

Watson struggled to an eight-over 78. That matched his worst round in a major, as he closed with 78 at the 2011 Masters.

"Just couldn't get anything going. Never got any rhythm, just everything was just a little off," Watson stated.

The big group in the afternoon featured the top three players in the world -- Luke Donald, defending champion Rory McIlroy and Lee Westwood. It was a tough day all around.

Donald had nine bogeys and nine pars in a round of nine-over 79. McIlory, who missed more greens in regulation Thursday than he did all of last year while winning at Congressional, had eight bogeys and a birdie for a seven-over 77.

Westwood had the best round of the three. He was four-over through six holes, but went minus-one the rest of the way. He stands alongside reigning PGA Champion Keegan Bradley and U.S. Ryder Cup captain Davis Love III in 40th place at three-over 73.

The day belonged to Thompson, who started with a bogey at the first. He holed out for birdie from a greenside sand bunker at the third. He went on to drop shots at the fifth and sixth, but it was all birdies and pars from there.

The 27-year-old got up and down for birdie from a bunker on the drivable par- four seventh. Thompson moved back to even-par as he rolled in a 15-footer for birdie on the ninth.

Thompson continued his climb up the leaderboard with back-to-back birdies at 11 and 12. He connected on his third birdie in four holes No. 14. That gave him five straight 3s.

Then, the television cameras showed up and he got a little nervous. Thompson parred 16 and 17, both par-fives, but settled himself at the last. He rolled in a 10-footer for birdie and a three-stroke lead.

"Got a little nervous there once all those cameras showed up. It's always a little bit of an adjustment. In that sense, I kind of wish I was Phil or Tiger, because you get the cameras from the beginning," Thompson commented. "But I really held it together. I just can't be more thrilled. "

Thompson is playing in just his third major championship, and broke par for the first time in his seven major championship rounds.

Woods tripped to a bogey on 14, but rebounded with a birdie on the par-five 17th. On the front side, he notched back-to-back birdies at four and five to move to minus-two. However, he bogeyed the sixth to fall three back.

"I was very surprised at how much the course had changed overnight, just how much speed that the fairways had picked up and the springiness of the greens. We knew the greens were going to be a little quicker, but I didn't think they would be this firm this early in the week," Woods said. "So we had to make a couple of adjustments with that."

Toms opened with a birdie on his first hole, but gave that back with a bogey at 11. After five straight pars, Toms birdied the 17th. The 2001 PGA Champion parred four straight from the 18th. Toms got to minus-two as he birdied the fourth. He stumbled to a bogey at six before parring his final two holes.

Rose opened with a bogey on the ninth. He moved into red figures with birdies at 14 and 17. He stumbled to bogeys on two and three, but birdies at eight and nine gave him a share of second.

McDowell, who won at Pebble Beach two years ago, mixed three birdies and two bogeys in his rounds of 69.

Watney started on the ninth and had a birdie and four bogeys in his first eight holes. He then holed his second shot on the par-five 17th for double- eagle. The moved him back to even-par. Watney parred seven in a row before a birdie on the seventh gave him a piece of second place.

NOTES: Thompson's previous majors were in 2008. He shared 29th at the U.S. Open and missed the cut at the Masters...Fourteen-year-old Andy Zhang, the youngest-ever U.S. Open participant, birdied his final hole to shoot 79 after starting triple-bogey, double-bogey... There is no longer a 10-shot rule. The cut will just be the top-60 and ties.