ATHENS, Greece – Andy Roddick hit one last errant shot into the net and hung his head, his medal hopes over. A short while later, Venus Williams was gone, too.

In back-to-back stunners at the Olympic tennis tournament, Roddick was upset by no. 16 Fernando Gonzalez of Chile 6-4, 6-4, and defending gold medalist Williams lost to Mary Pierce of France 6-4, 6-4. Both were third-round matches.

“I’m gutted right now. It’s not every day we get to play this,” Roddick said. “You can’t say, ‘Next year.’ “

For the first time since tennis returned to the Olympics as a medal sport in 1988, no U.S. woman will win a singles medal. That’s because in addition to Williams’s exit, no. 16 Chanda Rubin lost to no. 2 Amelie Mauresmo of France 6-3, 6-1, and Lisa Raymond was eliminated by Alicia Molik of Australia 6-4, 6-4.

“Just a pretty rough day for Americans,” U.S. coach Zina Garrison said.

Some did stick around, though. Mardy Fish got past Max Mirnyi of Belarus 6-3, 4-6, 6-1, and Taylor Dent beat Ivan Ljubicic of Croatia 6-4, 6-4 to reach the quarterfinals.

Martina Navratilova, in her first Olympics at age 47, and Raymond advanced to the doubles quarterfinals when their opponents, Mauresmo and Pierce, pulled out. Mauresmo developed a rash from a skin allergy during her win over Rubin.

Williams was largely her own undoing, with 51 unforced errors and five double-faults, including on match point. She said she wasn’t bothered by her sister Serena’s last-minute withdrawal from the Olympics with a knee injury.