Rusty Serena happy to progress

Second seed Serena Williams eased into the fourth round of the Australian Open while her sister's nemesis Carla Suarez Navarro's dream run continues in her first appearance in the Melbourne grand slam.

Williams produced a mixed performance in defeating Shuai Peng of China 6-1 6-4 and admitted afterwards she was still "feeling a little rusty".

Suarez Navarro, who ousted Venus Williams in three sets in the second round, defeated countrywoman Maria Jose Martinez Sanchez 6-1 6-4.

The world number 46 won the first set in just 27 minutes as she produced only two unforced errors and broke Martinez Sanchez every opportunity she had.

Martinez Sanchez put up a greater fight in the second set but was unable to make the most of her break-point opportunities, and Suarez Navarro closed out the match in less than 90 minutes.

She will play another Spaniard in the fourth round after Anabel Medina Garrigues, the 21st seed, upset 12th seed Flavia Pennetta of Italy 6-4 6-1.

Jie Zheng reached the fourth round for the first time with a 6-2 6-2 victory against Kateryna Bondarenko.

It was not a good day for the Bondarenko family as Kateryna's sister Alona, the 31st seed, also went out, going down 7-6 (9-7) 6-4 to eighth seed Svetlana Kuznetsova of Russia, who will now play Zheng.

Dominika Cibulkova, the 18th seed, defeated Virginie Rezzano 7-5 7-5 to set up a clash with fourth seed Elena Dementieva.