PARIS -- More than a decade ago in Compton, Calif., two sisters swatted strokes from opposite sides of a net, pretending the asphalt was the grass of Wimbledon, the hardcourts of the U.S. Open or the clay of the French Open.

When Venus and Serena Williams practiced Friday at Roland Garros, they were preparing to play each other for a Grand Slam title for the second time in nine months.

Their 1½-hour session a day before the French Open final captured the unique blend of competition and camaraderie their success has wrought.

During a break, they shared a towel, holding it aloft while Serena wiped her face with one end and Venus wiped her face with the other. At another juncture, Serena went to the net to talk with Venus, gesturing with her racket as both laughed.

Later, though, Serena threw her racket to the ground following each of four missed shots, once screaming her name and another time yelling, "Shoot!''

Imagine Arizona left-hander Randy Johnson slinging batting practice at the New York Yankees the day before Game 7 of the World Series, or Kobe Bryant and Jason Kidd playing some one-on-one hours before taking the court for the NBA Finals.

It just wouldn't happen.

But Venus and Serena have relished (at times) and dealt with (at times) being sisters who excel at the same sport.

"Right now I really want to win the French Open and I'm sure she does, too,'' Serena said. "I just have to go out there and fight.''

It's Sister Slam II, and there are plenty of reasons why there could be plenty of sequels: Their power, their athleticism, their increasing on-court patience, and their standing at Nos. 1 and 2 in the rankings as of next week.

As their mother, Oracene, put it: "They really haven't played up to their potential. They just haven't gotten there yet.''

The opponents in the men's final Sunday also will be familiar with each other -- Juan Carlos Ferrero and Albert Costa meet in the third all-Spanish title match in Paris since 1994. Ferrero beat Marat Safin 6-3, 6-2, 6-4 Friday, while Costa got past Alex Corretja 6-3, 6-4, 3-6, 6-3.

Unfortunately, the women's championship might just showcase the worst of Team Williams. That's because Venus (who's won Wimbledon and the U.S. Open the past two years) and Serena (the '99 U.S. Open champ) are capable of playing brilliant tennis against any opponent -- except, seemingly, each other.

Most of their seven previous meetings have been real duds, including September's U.S. Open final, which Venus won 6-2, 6-4 with the help of just seven winners. That, of course, was the first Grand Slam title decided by siblings since the very first major tournament: Wimbledon in 1884, when Maud Watson beat sister Lillian 6-8, 6-3, 6-3.

Venus owns a 5-2 edge against Serena, who did win their last match 6-2, 6-2 at Key Biscayne, Fla., in March.

"Venus pretty much gets every ball, and I pretty much get every ball,'' said Serena, 15 months younger than Venus, who turns 22 this month. "I think on this surface it's going to be maybe longer rallies than in the past. But that will probably be the only difference I can think of.''

When the new WTA Tour rankings are released Monday, they'll be the first siblings to sit 1-2: Serena's semifinal victory over defending champion Jennifer Capriati pushes her past Capriati to a career-best second, while Venus already was assured of overtaking Capriati at No. 1.

Besides being unprecedented, the sisters' new rankings mean they will be seeded Nos. 1 and 2 at tournaments, so they couldn't face each other until a final.

Their father, Richard, often says he gets too nervous watching his children square off, and he isn't in Paris as they accomplish what he long predicted they would.

He planned his daughters' tennis careers before they were born, teaching himself the sport from magazines and videos so he could coach them and even paying a psychiatrist to study the effects when sisters play each other.

"We learned,'' he says, "that tennis is the only game that's extremely rough on a family.''

Perhaps. But it's his family that's making tennis rough for other women.