SAN FRANCISCO (AP) ― Michael Thompson strung together four birdies on the back nine at Olympic Club that carried him to a 4-under 66 and a three-shot lead after the opening round of the U.S. Open on Thursday.

Tiger Woods was in a five-way tie for second place after a 69 that featured consecutive birdies late in his round, including a 35-foot putt that banged into the back of the cup on No. 5.

Only six players managed to break par in the opening round, which would have come as a surprise to none of the players. After opening with a birdie, Joe Ogilvie turned to his caddie and said, “Seventy-one more pars and we’re hoisting the trophy.” He shot 73.

Luke Donald, the No. 1 player in the world, is trying to capture his first major. It most likely won’t be this one. He failed to make a single birdie and shot 79. He played with Rory McIlroy, the defending champion and No. 2 in the world, who shot a 77. Lee Westwood, No. 3 in the world and the other member of the group, was 4 over through six holes and rallied for a 73.

The shocking numbers: The top three in the world ranking shot a combined 19-over par and had only three birdies.

“It shows how tough it is,” Donald said. “There aren’t that many opportunities out there.”

McIlroy said to a pool reporter that he simply got out of position. What didn’t need saying is that Olympic Club, with firm conditions and with fairways that are among the toughest to hit, is a far different test from Congressional, where the 23-year-old shattered the U.S. Open scoring record at 16-under 268.

The good news for McIlroy? His record is safe here.

“Anything just a little off and it really punishes you,” McIlroy said. “You have to be precise with your tee shots and your iron shots and leave it on the right side of the pins, and today I didn’t really do any of that.”

Nick Watney holed out from the fairway for an albatross 2 on the par-5 17th hole, sending him to a 69. Graeme McDowell, who won the U.S. Open two years ago down the coast at Pebble Beach, and Justin Rose shot 69 in the faster conditions of afternoon.

David Toms shot his 69 in the morning, relying on a solid short game and a good attitude.

“You really just have to concentrate, give it your all on every shot and never give in to the golf course, because it will punish you if your attitude is not good, if your concentration is not good,” Toms said. “There’s just too many hard shots out there to really ever give in to it and not be there.”

The group at 70 included Jim Furyk, Matt Kuchar and 17-year-old Beau Hossler, already playing in his second U.S. Open.

Thompson’s game seems to work on this quirky, tree-lined course built on the side of a giant dune that separates the Pacific Ocean from Lake Merced.

He was runner-up in the 2007 U.S. Amateur at Olympic Club and couldn’t wait to get back.

After a roller-coaster of a front nine that featured consecutive bogeys and holing a bunker shot for birdie on the downhill par-3 third hole, Thompson hit his stride on the back nine, even if hardly anyone was watching.

He made five consecutive 3s ― three of them birdies ― and closed his dream round with a 10-foot birdie putt on the short, tough 18th for the lead. Thompson took only 22 putts.

“On the back side, the putter ... seems like every putt went in the hole,” said Thompson, a 27-year-old playing his first U.S. Open as a pro. “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.”