PARIS -- Against anyone else, on any surface, Serena and Venus Williams are just about unbeatable, boasting an unequaled blend of power and mobility.

Against each other, they become almost ordinary.

Still, there's nothing the Slammin' Sisters would like better than to keep on settling major titles among themselves, rolling through opposite sides of the draw until there's no one left to beat in the final but each other.

That's been that case at two of the past three Grand Slam tournaments, with Serena getting the best of her Big Sister at the French Open, beating her 7-5, 6-3 Saturday for the championship -- nine months after Venus came out on top at the U.S. Open.

"When you're a top player, you just do everything a little bit better than the next player: You serve better, you move better, you fight better, just those kinds of things,'' Venus said. "Serena does it better than the next player.''

In Monday's new rankings, Venus will be No. 1, and Serena No. 2, the first siblings to sit 1-2. That means they will be seeded Nos. 1 and 2 at tournaments, potentially setting up more finals, including at their next event: Wimbledon.

They share the tour lead with four titles apiece in 2002, and their combined career earnings now top $17 million.

"It's better that I won against Venus,'' Serena said Saturday, "because at least we both took home the maximum amount of money and (ranking) points.''

A telling stat: Venus is 0-2 against Serena this year, 35-3 against everybody else. In the French Open, Venus didn't lose a set through her first six matches, dropping a total of only 29 games.

Then she had to deal with Serena, who eliminated defending champion Jennifer Capriati in the semifinals and has won the last two sibling showdowns to improve to 3-5 against Venus.

Just as in September's U.S. Open final and most of their previous seven meetings, Team Williams didn't display its top tennis in the final at Roland Garros. They combined for 101 unforced errors, 14 double faults and 13 breaks of service. Four games ended with double faults.

It could be a result of facing a top player, or of playing someone who knows the other's game oh-so-well -- they practiced together on center court just a few hours before competing there -- or it could stem from the difficulty of trying to be dominant against a sibling.

"I was thinking when I was out there, 'Gosh, my Dad would be very upset at the way we're both playing right now,' " Serena said. "I was not mentally focused enough.''

They turned their backs between points and stared at the clay while heading to changeovers. There were none of the smiles they share during training sessions or when one is watching from the player's guest box as the other plays an early round match.

And yet, when they hugged at the net after one last error ended the final, they easily dropped their stiff-faced veneers, like someone who takes off a sweater when the sun comes out from behind clouds.

When Serena hoisted her trophy, Venus grabbed their mother's camera and mixed in among the scrum of photographers to shoot some pictures for the family album.

It was a markedly different reaction from the other time Serena won a major title -- the family's first, at the 1999 U.S. Open. Venus watched that match next to her parents with a forlorn look on her face that said, "Why couldn't that be me?''

Clearly, the sisters are maturing off the court as quickly as they are on it.

"They've handled everything that's come their way so beautifully,'' said Chris Evert, owner of 18 Grand Slam tournament titles and now an NBC analyst.

With serves that regularly top 105 mph, laserlike strokes off both wings, rapidly developing net games, and an uncanny ability to run down opponents' apparent winners, the sisters are changing the way women's tennis is played. And the past two weeks have rendered silly the thought that clay's slowness would thwart them.

Venus won Wimbledon and the U.S. Open each of the past two years, meaning a Williams has captured six of the past 11 majors.

"Hopefully, we can build a rivalry and we'll be able to do this a lot,'' said 20-year-old Serena, 15 months younger than Venus. "Make a legacy, then retire champions.''

They're well on their way.