Fourth seed Russia Maria Sharapova, fifth seed Svetlana Kuznetsova of Russia and seventh seed Serena Williams of the United States advanced to fourth round of the Australian Open on Friday.

Sharapova, the Wimbledon champion, cast aside China's Li Na 6-0, 6-2, advancing into the last 16.

The 17-year-old Russia will play 15th seed Silvia Farina Elia of Italy in the next round.

Serena joined her elder sister Venus Williams in the last 16 as she wiped Indian teenager Sania Mirza 6-1, 6-4.

After winning the first set easily, Williams faced strong resistance from Mirza who overcame her nerves and did her best fighting back.

"I was happy with the match today because in the second set - I was getting girls who weren't giving me any pace - but today she was giving me lots of hard balls," Williams said after the match.

"It was good to see someone from India for the first time do so well - and I told her to keep fighting," she said.

"I think she had a very solid game, she's so young, she's only 18 and I see a very bright future for her," said Williams.

Kuznetsova beat Argentine Mariana Diaz-Oliva 6-3, 7-6.