PARIS -- Serena Williams figured an apology was in order.

She had just overpowered Barbara Schett 6-0, 6-0 Friday at the French Open in what amounted to a 40-minute practice session.

So when they met at the net after the third-round match, Williams patted Schett on the back and offered these kind words: ``I'm sorry.''

It was a dose of compassion, something not seen much amid all the showboating in sports today.

``That was strange,'' Schett said. ``I've never heard that from an opponent.''

No. 4 Justine Henin-Hardenne and No. 5 Amelie Mauresmo, the only players to beat Williams this year, also had straight-set wins. But Williams' victory stood out.

``It wasn't as easy as it looked,'' the defending champion insisted.

Hmmmm.

Williams compiled a 23-2 edge in winners, drawing a collective "Ooooh!'' from fans by stepping up to drive one forehand to a corner. She dropped a total of six points in the second set and generally looked far better than sister Venus did in winning a three-set ordeal Thursday against 110th-ranked Evie Dominikovic.

Don't forget, Schett used to be in the top 10 and she upset Venus at Roland Garros in 2001.

But she hasn't been past the quarterfinals at a major. Serena Williams is trying to become the first player with five straight major titles since Steffi Graf in 1988-89.

Given the way Williams played, maybe fellow American Meghann Shaughnessy caught a break by losing to No. 16-seeded Ai Sugiyama, 6-1, 6-4. Sugiyama faces Williams next.

The warmest day yet at Roland Garros -- muggy and in the mid-80s -- provided motivation to work quickly, and No. 4 Justine Henin-Hardenne and No. 5 Amelie Mauresmo won in straight sets. Henin-Hardenne beat Dally Randriantefy 6-1, 6-1, and Mauresmo eliminated Fabiola Zuluaga 6-3, 6-4.

No. 8 Chanda Rubin rallied to beat fellow American Laura Granville 2-6, 6-1, 6-3.

Schett upset Venus Williams in the first round two years ago, but she was no match for the younger Williams. The Austrian had four break points early but soon found herself overwhelmed.

"When I stepped out there and I lost the first couple of games, I thought, 'This is a difficult day,''' Schett said.

Williams closed the first set with a remarkable exchange that left multiple track marks on her side of the clay.

She raced toward a drop shot and scooped it back as she went sliding off the court. Then she reversed direction to hit a running, lunging backhand for a winner as she skidded across the other sideline.

"I'm running really fast here, and that's great,'' Williams said. "I guess it's the fittest I've been all year.''

Schett managed to hit her only backhand winner in the final game, then raised both arms in mock jubilation as the center-court crowd cheered. But she dumped another backhand into the net on match point, then walked off the court shaking her head and smiling in chagrin.

Williams also smiled. But with four rounds to go for another title, she claimed there's room for improvement.

"I can serve better, for sure,'' she said.