At a tournament last week, a fan gave Venus Williams a little black doll, complete with two interchangeable beaded wigs. The toy bore a slight likeness to both Venus and her younger sister, Serena, although one important item was missing. The doll had no silver trophy in its hand.

That's something Venus would like to rectify in real life by winning the title at this U.S. Open. As the No. 3 seed, she is a favorite here, although she will have to get through several tough opponents -- including perhaps Serena -- to win her first Grand Slam title. The sisters are on opposite sides of the draw, so they could not meet until the final, a prospect that has become the main buzz at a tournament struggling with the early departures of men's top seed Pete Sampras and two-time defending champion Patrick Rafter.

"Now that would be really exciting, because either way, one of us would win our first Grand Slam," said Serena, who has won three WTA Tour titles but lost to Venus when the sisters met in a final in Key Biscayne, Fla., earlier this year. In all, Venus has seven titles, four this year alone.

"When I am on my game, no one can beat me," Serena continued. "I definitely would [expect to win]. I'm sure she would, too, so it would be a very good match."

Both sisters advanced today, with Serena moving into the third round with a 6-4, 6-2 win over Jelena Kostanic. Venus earned a walkover into the fourth round when Henrieta Nagyova withdrew with a right wrist strain.

No. 14 seed Sandrine Testud was not so fortunate, falling to Spain's Magui Serna, 6-3, 6-3, nor was No. 8 seed Carlos Moya, who had to retire from his match with a bad back. Rockville's Paul Goldstein also lost his match, falling to Jan Kroslak, 5-7, 6-4, 6-4, 6-3, although Andre Agassi, Monica Seles and Lindsay Davenport all advanced.

Seles and Davenport are lurking in Serena's half of the draw; in Venus's side sits top seed Martina Hingis. But while each sister has plenty to plow through just to get out of her half of the draw, on Monday their father, Richard, predicted an all-Williams final.

Today he amended that statement to say he "had confidence" his daughters would reach the final here, remarking that "everyone here should have that, or they shouldn't be out there." Still, his statements have put some pressure on the sisters, and he hasn't stopped talking.

Today he remarked that "I don't like tennis very much," and said he preferred to come to only three events a year, allowing his wife, Oracene, to travel with Venus and Serena.

Asked why he raised two daughters to be professional tennis players if he didn't like the sport, he said, "So they could make millions of dollars. If UCLA could train a monkey to answer the telephone, you can train a human to do anything."

His statements have bothered other players, including Hingis, who was disturbed about hearing him predict an all-Williams final. She accused one of the Williamses -- it was unclear which -- of having "a big mouth," and noted that "they always talk a lot."

"It's more pressure on them," Hingis continued. "Whether they can handle it or not, now that's the question. Of course, the other players are pretty pumped up."

But if their father's comments bother the sisters, they are not saying it, and they are not showing it. While they weren't entirely pleased with their play in early matches, neither has been tested.

They also are having few problems in the doubles draw, where they are entered together. Today's match against Japanese partners Miho Saeki and Yuka Yoshida took just 57 minutes, with the Williamses winning, 6-2, 6-3.

As for Hingis's words, Serena tried to be polite, although she did note that "I personally don't think my mouth is big -- I mean, if you're looking at it."

Of Hingis, she added: "It's her problem. She says things, just speaks her mind. I guess it has a little bit to do with not having a formal education. But you just have to somehow think more, you have to use your brain a little more in the tennis world. It just literally does not pay to say anything negative and bad about anyone."

Venus, 19, and Serena, 17, have taken enough classes to get their high school diplomas, and both will be taking classes at a Florida community college in the fall. They are learning languages -- Serena is studying Portuguese, Venus is learning Italian -- and both seem to have an unusual affinity for wrestling. (Venus's WTA Tour biography lists one of her interests as sumo wrestling; Serena's says that in her next life she would like to come back as either a World Wrestling Federation competitor or as a race car driver.)

But for these two weeks, their only interest is tennis, with their eyes on a prize that both covet but only one can have.

"I love winning tournaments," Venus said, laughing. "As far as Serena and I being on each side, we can just get our work done as best we can. I hope we can both do well. That would be pretty great."

U.S. Open at a Glance

Where: USTA National Tennis Center, Flushing Meadows, N.Y.

When: Through Sept. 12.

TV: USA, 11 a.m., 7:30 p.m.

Defending champions: Patrick Rafter, Lindsay Davenport.

Top seeds: Pete Sampras, Martina Hingis.

Yesterday's results: Men -- Andre Agassi (2), United States, def. Axel Pretzsch, Germany, 6-3, 6-2, 6-1; Marcelo Rios (10), Chile, def. George Bastl, Switzerland, 4-6, 6-3, 6-2, 6-3; Richard Krajicek (12), Netherlands, def. Lorenzo Manta, Switzerland, 6-2, 6-4, 6-1. Women -- Venus Williams (3), United States, def. Henrieta Nagyova, Slovakia, walkover; Monica Seles (4), United States, def. Silvia Farina, Italy, 6-2, 6-3; Mary Pierce (5), France, def. Gala Leon Garcia, Spain, 6-2, 6-3; Serena Williams (7), United States, def. Jelena Kostanic, Croatia, 6-4, 6-2; Julie Halard-Decugis (9), France, def. Li Fang, China, 6-2, 6-3; Nathalie Tauziat (11), France, def. Maria Antonia Sanchez Lorenzo, Spain, 7-5, 4-6, 6-1.

Today's featured matches: Men -- Paul Haarhuis, Netherlands, vs. Gustavo Kuerten (5), Brazil; Richey Reneberg, United States, vs. Todd Martin (7), United States; Greg Rusedski (9), Britain, vs. David Prinosil, Germany; Mariano Puerta, Argentina, vs. Tommy Haas (14), Germany; Fredrik Jonsson, Sweden, vs. Nicolas Lapentti (16), Ecuador; Jan-Michael Gambill, United States, vs. Fabrice Santoro, France; Cristiano Caratti, Italy, vs. Goran Ivanisevic, Croatia. Women -- Martina Hingis (1), Switzerland, vs. Sandra Kloesel, Germany; Anke Huber, Germany, vs. Jana Novotna (8), Czech Republic; Patty Schnyder, Switzerland, vs. Arantxa Sanchez-Vicario (10), Spain; Barbara Schett (12), Austria, vs. Virginia Ruano Pascual, Spain; Mary Joe Fernandez, United States, vs. Dominique Van Roost (13), Belgium; Amelie Mauresmo (15), France, vs. Tara Snyder, United States.