SAN FRANCISCO -- Alvaro Quiros heard the roars and still didn't know what happened.

After all, he was too far away to even see his ball.

The Spaniard teed off with driver from 288 yards out on the par-4 seventh Wednesday. The ball rolled up the elevated green, caught the second slope and trickled into the hole for an extraordinary ace.

The grandstand crowd stood and delivered a roar that echoed across The Olympic Club so loud one might've thought the U.S. Open had begun a day early.

"We thought it was going to be more in the middle of the green. Suddenly, we see the people stand," Quiros said. "Gonzalo (Fernandez-Castano) said, 'I think you holed it.' And I said, 'No, it probably just touched the flag.' And then we start to walk and the people start screaming again. I said, 'OK, probably. Maybe.' When we start to get closer to the green, people start congratulating me, and that's when I realized it was an albatross."

Quiros originally pulled out a 3-wood until his caddie talked him into driver -- "the perfect club," he said -- at the last moment. He waved to the fans and tipped his cap walking up the green, pulled the ball out of the hole and tossed it into the grandstand.