Williams sisters both win at Stanford

Serena Williams, seeded No. 1, ousted Melinda Czink 6-3, 7-6 (9-7) to set up a quarterfinal match against Samantha Stosur.

Venus Williams, the second seed, was a 6-1, 7-5 victor over Alla Kudryavtseva.

Marina Sharapova will face Venus Williams in the quarterfinal round.

In other second-round matches Thursday, Agnieszka Radwanska outlasted Daniela Hantuchova 6-4, 6-7 (6-8), 6-1 and Marion Bartoli got past Melanie Oudin 7-5, 6-4.

If the Williams sisters play in the championship match, it will be their fourth meeting of the year. The most recent came in the Wimbledon final, which Serena won 7-6 (7-3), 6-2.

Copyright 2009 by United Press International.