WIMBLEDON, England — Don't tell Serena Williams that sister Venus is the one to beat at Wimbledon.

"I would never sit here and say she's the favorite when I'm still in the draw," she said, bristling at the suggestion. "That's not me. I always believe that I'm the favorite. Even if I'm not the favorite, I'm always going to believe that I am."

The Williams sisters, who between them have won six of the last eight Wimbledon titles, are one round away from a third Wimbledon title matchup and seventh Grand Slam championship showdown. Neither has dropped a set so far, and their power games have set them apart from the rest of the women's field.

"That would be amazing if we both were in the final," defending champion and four-time winner Venus said after beating Tamarine Tanasugarn 6-4, 6-3 Tuesday to reach the semifinals.

Two-time champ Serena caught some of her sister's match before going out and sweeping Agnieszka Radwanska 6-4, 6-0.

"Watching the competition a little bit," she said.

Next up for sixth-seeded Serena on Thursday is Zheng Jie, who became the first Chinese player to reach the semifinals of a Grand Slam by beating Nicole Vaidisova 6-2, 5-7, 6-1. The 133rd-ranked Zheng is also the first wild-card entrant to reach the women's semis at Wimbledon and second at any Grand Slam.

No. 7 Venus will next face No. 5 Elena Dementieva, who wasted a 5-1 lead and two match points in the second set before beating fellow Russian Nadia Petrova 6-1, 6-7 (6), 6-3 to reach her first Wimbledon semifinal.

The women have a day off today, which is set aside for the men's quarterfinals. For the first time at a Grand Slam in the 40-year history of the Open era, all eight quarterfinalists are from Europe.

The draw seems headed to a third straight final between five-time champion Roger Federer and Rafael Nadal.

Federer was scheduled first up on Centre Court against Mario Ancic, the last player to beat him on grass — in the first round of Wimbledon in 2002.

Nadal, bidding to become the first man to win the French Open and Wimbledon in the same year since Bjorn Borg in 1980, was paired against Andy Murray. The 12th-seeded Murray, playing in his first Grand Slam quarterfinal, is trying to become the first British man to win the title in 72 years.