The second seed Serena Williams has had a hollow win at the Australian Open tennis tournament in Melbourne, to advance to the quarterfinals.
Williams was trailing by a set when Victoria Azarenka of Belarus retired because of illness.
In other women's action, the fourth seed Elena Dementieva has cruised into the quarterfinals after sweeping past the Slovakian Dominika Cibulkova in straight sets 6-2, 6-2.
Dementieva will now meet the unseeded Spaniard Carla Suarez Navarro, who also advanced today after a straight sets victory over compatriot Anabel Medina Garrigues.
In the men's section, the sixth seed Gilles Simon of France is through to the quarterfinals after compatriot Gael Monfils retired hurt with a wrist injuring during their match.
Simon will play the winner of the match between top seed Rafael Nadal of Spain and 13th seed Fernado Gonzales of Chile.
