Nick Dougherty, taking advantage of rain-softened conditions with a precise short game, fired a two-under-par 68 to forge one shot clear in the US Open first round on Thursday.
While world number one Tiger Woods battled to a 71 at Oakmont Country Club, one of golf's toughest layouts, Dougherty carded four birdies and two bogeys in his lowest score at a major championship.
"I'm delighted with that," the 25-year-old told reporters after raising hopes of a first European major victory in eight years.
"We had it as good as it could be this morning after the thunderstorm yesterday because you can stop the ball on some of the holes.
"I didn't play that well from tee to green but my short game was red-hot," added Dougherty, who took only 11 putts on the back nine.
Dougherty, who won his only European Tour title at the 2005 Singapore Masters, birdied three of the last eight holes to end his round one ahead of big-hitting Argentine Angel Cabrera.
"It's always tough to break par in the US Open and you have to take care here on every shot," said Cabrera, who was level with Dougherty before bogeying the par-four 17th.
Twice US Masters champion Jose Maria Olazabal, who came close to an ace at the par-three sixth, and American Bubba Watson, making only his second appearance in the tournament, were next best on 70.
Woods, third-ranked Jim Furyk, defending champion Geoff Ogilvy of Australia and Fiji's Vijay Singh were among a group of 16 bunched on 71.
STUMBLING START
Woods, bidding for his 13th major victory, made a stumbling start after finding a fairway bunker off the first tee but was delighted with his par-birdie-par finish.
"That was a nice way to end the round," said the US Open champion at Pebble Beach in 2000 and Bethpage Black in 2002. "On this course, 71 is right there.
"If you shoot three, four or five over par, you're still in the tournament and you've got to hang in there. It's as soft and receptive as you're possibly going to have it and not too many of the guys are taking it to the course."
Ernie Els, US Open champion at Oakmont in 1994, opened with a 73 and three-times major winner Phil Mickelson, who has been nursing a wrist injury for the last two weeks, carded a 74.
Only two players in the 156-strong field returned sub-par scores on a day of typical US Open grinding when the average was 75.32.
American David Toms, who ended up with a 72, got to three under after 12 holes and Briton Justin Rose (71) was two under after 13 before both fell back over the punishing five-hole stretch starting at the par-four fifth.
Several big names effectively shot themselves out of contention, twice champion Retief Goosen double-bogeying the last for a 76 and world number six Henrik Stenson and Spaniard Sergio Garcia limping to 79s.