NEW YORK - Finished with a mostly matter-of-fact victory in the U.S. Open's third round Friday, defending champion Serena Williams switched into a yellow T-shirt with this bit of wisdom in blue script: "Can't spell dynasty without nasty."
Asked about it, Williams took the chance to push a sponsor's new clothing line. Moments later, she found herself discussing her autobiography, though she refrained from shouting: "Available at a bookstore near you!"
About the only thing Williams doesn't need to sell anyone on is the quality of her tennis, particularly at Grand Slams. By beating serve-and-volleyer Maria Jose Martinez Sanchez 6-3, 7-5, Williams improved to 28-1 in the past five majors.
"You can never underestimate anyone," said Williams, the second seed. "Some people, some days, they have great days. I just go and look at every opponent as the best player in the world."
Perhaps some of her colleagues should take that approach.
This has been a topsy-turvy U.S. Open for the women: No. 8 Victoria Azarenka's 4-6, 6-2,6-2 loss to No. 26 Francesca Schiavone on Friday came a day after No. 4 Elena Dementieva and No. 5 Jelena Jankovic were upset. All told, 11 of the 20 highest seeds are gone, and the third round is only halfway done.
"Now there is not a lot of difference between players," Sanchez Martinez said. "I think anyone can win any match."
Williams' older sister Venus, seeded third, avoided adding to the list of upsets when she defeated 46th-ranked Magdalena Rybarikova 6-2, 7-5 on Friday night. Venus struggled with her serve and appeared to have some problems with her left knee, which she injured Monday. She again wore wide strips of tape above and below the joint.
Venus set up a fourth-round match against 2005 winner Kim Clijsters, who cruised to a 6-0,6-2 victory over Kirsten Flipkens. Clijsters, returning to tennis after a two-year break, is unseeded.
The men's winners included No. 2 Andy Murray, No. 6 Juan Martin del Potro, No. 7 Jo-Wilfried Tsonga and No. 9 Gilles Simon. None of the top 10 men had dropped a set until 2008 runnerup Murray's slip in his 6-2,3-6, 6-0, 6-2 win over Paul Capdeville, ranked 87th. Murray, Capdeville said, "has a shot in store for the moments he needs them the most. That's the difference."
One upset seemed to be in the making, but 135th-ranked Jesse Levine, a former Gator from Boca Raton, wasted a two-set lead and lost to No. 16 Marin Cilic 4-6, 2-6, 6-0, 6-3, 6-0.
Men: Andy Murray (2) d. Paul Capdeville 6-2, 3-6, 6-0, 6-2; Juan Martin del Potro (6) d. Jurgen Melzer 7-6 (8-6), 6-3, 6-3
Women: Serena Williams (2) d. Maria Jose Martinez Sanchez 6-3, 7-5; Venus Williams (3) d. Magdalena Rybarikova 6-2, 7-5
Key matches today
Men: Roger Federer (1) vs. Lleyton Hewitt (31); Andy Roddick (5) vs. John Isner
Women: Dinara Safina (1) vs. Petra Kvitova; Maria Sharapova (29) vs. Melanie Oudin
TV: 11 a.m., Ch. 10; 7 p.m., Tennis Channel