BEIJING, China - For the third straight week - Seoul two weeks ago, Tokyo last week and Beijing this week - and sixth time all year, an event's Top 4 doubles seeds are through to the semifinals. It was not smooth sailing for any of the seeds in quarterfinal action, though, on Thursday at the China Open.

No.1 seeds Kveta Peschke and Katarina Srebotnik were a break down in each set but got past Anabel Medina Garrigues and Anastasia Pavlyuchenkova, 64 76(5). It was their 50th match victory of the season, most on the WTA and 15 ahead of second-place Sara Errani and Roberta Vinci.

Second-seeded Liezel Huber and Lisa Raymond edged fellow Americans Raquel Kops-Jones and Abigail Spears to extend their win streak to 12 matches, second-longest of the year behind Peschke and Srebotnik's 14.

No.3 seeds Gisela Dulko and Flavia Pennetta shook off a slow start to top No.7 seeds Peng Shuai and Zheng Jie, 46 62 103. Pennetta is having an especially good week, as she is also into the quarterfinals in singles.

Fourth-seeded Vania King and Yaroslava Shvedova had a see-saw affair with eighth-seeded Daniela Hantuchova and Agnieszka Radwanska. King and Shvedova recorded a first set bagel in 21 minutes. They then fell into a 5-1 hole in the second set before reeling off six straight games while surviving two set points for the 60 75 triumph. It was a far cry from their only previous clash, won 61 60 by Hantuchova and Radwanska in the quarters of Indian Wells in March.

Peschke and Srebotnik will square off with King and Shvedova in Friday's semis, while Huber and Raymond will take on Dulko and Pennetta in a rematch of last week's Tokyo final won by Huber and Raymond in a match tie-break.