San Francisco - South Africa's Branden Grace eagled the par-five 17th on Thursday to seize a share of the early US Open first-round lead, alongside American Kevin Na.
Live scorecardGrace, a three-time winner on the European Tour this season, teed off on the ninth hole at The Olympic Club's Lake Course, and birdied 10 and 11 before a bogey at 12 dropped him back to one-under.
Playing partner Na had just moved atop the leaderboard at three-under through nine holes with his fourth birdie of the day at 17 when Grace rolled in his eagle putt.
They were one shot in front of American Jason Bohn, whose two birdies included one on Olympic's 520-yard first hole, all the more imposing playing as a par-four instead of the par-five it was in the four prior US Opens held here.
Another half-dozen players on one-under included Ireland's Padraig Harrington, Scotland's Marc Warren and amateur Nick Sherwood.
The marquee group of Tiger Woods, Phil Mickelson and Bubba Watson teed off on nine and encountered drama right away.
Mickelson lost his ball in the cypress trees and had to return to the tee, escaping with a bogey. The five-time US Open runner-up was four-over through eight holes.
Masters champion Watson was also four-over through eight, his four bogeys including one at the 16th, one of just two par-fives on the course.
Woods opened with a steady five straight pars before a bogey at 14 and was one-over through eight.
The afternoon's glamour group of world number one Luke Donald, number three Lee Westwood and defending US Open champion Rory McIlroy were due to tee off later.