Williams sisters advance

MELBOURNE, Australia -- Serena Williams moved a step closer to successfully defending her Australian Open title and extracted some family revenge Saturday with a 6-0, 6-3 victory over Carla Suarez Navarro.

Last year, Suarez Navarro beat Venus Williams in the second round and made it to the quarterfinals.

The Spaniard didn't even get close this time, and the Williams sisters remained on course for a semifinal meeting when Venus held off Australia's Casey Dellacqua 6-1, 7-6 (4), closing with an ace on her third match point.

Serena's only real difficulty was in closing the first set, needing eight set points in a game that went to deuce 13 times and lasted longer than the previous five games combined.

After she missed her seventh set point, pushing a backhand too long, the top-ranked Serena dropped into a sitting position on the court with a look of disbelief.

"It was definitely the toughest 6-love set," she said. "I thought, 'OK, Serena, don't put too much pressure on this. Worst-case scenario it will be 5-1.' But way to keep fighting.

"At the end of day I'm glad I didn't lose that game."

Serena, who has won the Australian title each odd-numbered year since beating Venus in the 2003 final, will play No. 13 and local hope Samantha Stosur, a 6-4, 6-1 winner over Italian Alberta Brianti.

Venus will play No. 17 Francesca Schiavone of Italy, who ousted No. 10 Agnieszka Radwanska 6-2, 6-2.

Venus is thinking final, which would mean beating Serena along the way.

"Of course I want to progress well to the final, that is my goal," Venus said. "So far, I'm getting closer. You know how it works. Just got to play well every match."

In other women's matches, U.S. Open runner-up Caroline Wozniacki of Denmark beat Shahar Peer of Israel 6-4, 6-0.

Wozniacki will face Li Na of China, who equaled her best run at Melbourne Park when she advanced 7-5, 3-6, 6-2 over 2008 semifinalist Daniela Hantuchova.

Li is one win away from reaching the quarterfinals at a third major.

No. 7 Victoria Azarenka of Belarus had a 6-0, 6-2 win over Italy's Tathiana Garbin to set up a fourth-round match against No. 9 Vera Zvonareva of Russia, who beat Argentina's Gisela Dulko 6-1, 7-5.

The Associated Press contributed to this report.