Andy Roddick (search) hit one last errant shot into the net and hung his head, his medal hopes over. A short while later, Venus Williams (search) was gone, too. In back-to-back stunners at the Olympic tennis tournament, Roddick was upset by No. 16 Fernando Gonzalez (search) of Chile 6-4, 6-4, and defending gold medalist Williams lost to Mary Pierce (search) 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.'"

It was bad day for the U.S. team. 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. Only Taylor Dent won, beating Ivan Ljubicic of Croatia 6-4, 6-4.

Williams, whose bid for a second straight doubles title ended in the first round, was broken in the last game of each set against Pierce, a two-time major champion.

Roddick had a chance to extend his match in the final game, getting four break points, but he failed to convert any. That was a pattern throughout the match: Roddick wasted his chances, and Gonzalez converted his.

Gonzalez wallops each shot with all his force, and he was on target Wednesday, delivering 23 winners to Roddick's six.

"Normally, when you play with Fernando, there's a lot more valleys with those peaks," Roddick said.

The hardest server in the world, Roddick did compile 13 aces but was broken once in each set, including at love to fall behind 5-4 in the second. By then, though, he appeared distracted by an extended argument with the chair umpire that began late in the first set and dragged into the second.

Roddick's defeat came a day after No. 1 Roger Federer lost to 18-year-old Tomas Berdych of the Czech Republic, leaving the men's tournament without its two biggest stars. It was a striking change of fortunes for players who met in the Wimbledon final last month, when Federer won his second straight title there.

Now both need to regroup quickly before heading to New York for the U.S. Open, which starts Aug. 30 and is played on the same hard courts used for these Olympics.

Roddick will be defending his only Grand Slam title there, and he'll have to play better than he did in Athens. He barely escaped the second round Tuesday night, saving three match points before beating Tommy Haas 9-7 in the third set.

Maybe that drained Roddick, because he quickly found himself in trouble Wednesday, broken in the third game of the match. He missed a forehand, then double-faulted twice, and Gonzalez smacked a backhand down the line to go up 2-1. Gonzalez raised a fist in Roddick's direction and yelled "Vamos!"

Still, Roddick had an opening when Gonzalez served for the first set at 5-4.

Unable to do much against the Chilean's serve all match, Roddick was at 15-30 when he got a good read on a second serve and smacked a deep forehand return. It landed right at the baseline near Gonzalez's feet.

Looking down at the ball, Gonzalez paused, and the line judge called the shot out. Chair umpire Cedric Mourier of France quickly overruled, saying the point should be replayed.

First Gonzalez questioned the overrule, putting his palms up as if to say, "Why did you do that?" while talking to Mourier. Then Roddick took his turn for a brief talk with the chair umpire.

They replayed the point, which Gonzalez won with a volley. On the next point, Roddick dumped a forehand return into the net and reared back to spike his racket on the court — but held on to it, as if he thought better. Roddick then dropped a forehand into the net, ending the set.

At the changeover, Roddick resumed his conversation with Mourier, making the case that Gonzalez's body language persuaded the line judge to call Roddick's return out.

"I could see it, clear as day," Roddick said.

He kept talking while waiting at the baseline to start serving, then picked up the argument again during the next changeover.