New York ? Maria Sharapova and her father often trade glances between points. In the stands, Dad pounds his fist on his chest, and she mimics the signal.

It represents a simple message — “Play with heart!” — but the Wimbledon champion didn’t use the gesture during a 4-6, 6-2, 6-3 loss to Mary Pierce in the U.S. Open’s third round Saturday.

Instead, right over her heart and just below her sponsor’s logo, Sharapova’s silver dress carried a plain black ribbon. She wore it in memory of the more than 340 people, nearly half children, killed in a hostage-taking at a school in her native Russia.

“I lost today, but I still have to move on. It’s not the end of the world,” said Sharapova, who double-faulted 14 times and dropped the final five games. “There are a lot more important things in the world going on right now.”

As far as tennis goes, her exit was the day’s most significant development, more surprising than No. 3 Carlos Moya’s 4-6, 6-4, 6-3, 6-7 (5), 7-5 collapse against 100th-ranked Oliver Rochus of Belgium, at 5-foot-5 the shortest ATP Tour regular.

Otherwise, the top players advanced in straight sets, including Justine Henin-Hardenne, Lindsay Davenport, Roger Federer and Andre Agassi.

Venus Williams defeated No. 20 Chanda Rubin 7-6 (4), 6-3.

Agassi’s next opponent will be Sargis Sargsian, who erased a two-set deficit and saved two match points to beat Paul-Henri Mathieu 4-6, 4-6, 6-4, 6-2, 7-6 (4) in 4 hours, 41 minutes. Add in his second-round win over No. 10 Nicolas Massu — at 5:09, the second-longest match in tournament history — and Sargsian broke the record for longest consecutive Open matches.

“I don’t know how I did it,” said Sargsian, an Armenian ranked 54th.

Often mistaken by security guards for a ball boy or a junior player, Rochus entered the tournament with a 76-101 career mark and an 0-4 Open record. That last fact prompted Moya to ask incredulously, “He never won?”

Now Rochus is one victory shy of .500 in New York. The Belgian knocked off No. 27 Mario Ancic, a Wimbledon semifinalist, in the first round, and can reach his first Grand Slam quarterfinal by beating No. 22 Dominik Hrbaty.

“That’s why you don’t underestimate anybody,” said Agassi, a 6-4, 6-2, 6-3 winner over No. 25 Jiri Novak.

Moya won the 1998 French Open, but he’s been a quarterfinalist at just three of his past 20 majors, and he was largely his own undoing Saturday. He made 61 unforced errors, and double-faulted on match point.

When they met at the net, Rochus looked straight at the 6-foot-3 Moya’s chest.

“It happens in tennis sometimes: You don’t know why you play good,” Rochus said.

Henin-Hardenne beat Lisa Raymond, 6-4, 6-3, Davenport slipped past No. 26 Elena Bovina, 7-6 (7), 6-2, and Federer’s 6-0, 6-4, 7-6 (7) victory over No. 31 Fabrice Santoro put him in the round of 16 for the fourth straight year.

“The way he’s playing now,” Santoro cautioned, “he doesn’t have to be scared of anyone.”

But Federer never has been past the Open’s fourth round. If he does reach the quarterfinals, his opponent could be Agassi, an eight-time major champion.

Agassi’s right sneaker’s sole tore away against Novak, so he reached into his bag for a plastic tube of glue and reattached it. That was the biggest blip in another easy victory.

“You never know when you need your best tennis,” Agassi said.