MELBOURNE, Jan. 19 (Xinhua) -- Defending champion Amelie Mauresmo breezed into the fourth round of the Australian Open with a comfortable 6-3 6-1 victory over Czech Eva Birnerova here on Friday.

    Seeded second behind Russian Maria Sharapova, Mauresmo is keen to claim the Australian title with a legitimate final win.

    Her win last year was clouded by the mid-match retirement of Belgian Justine Henin-Hardenne who complained of a stomach illness.

    Earlier, Serena Williams kept alive her chances of a third Australian crown when she downed the No.5 seed, Russian Nadia Petrova.

    Williams, unseeded after being out through injury, was swamped in the first set and down 3-5 in the second but fought back to clinch a 1-6 7-5 6-3 victory.

    And Russia's Svetlana Kuznetsova, the No.3 seed, bounced into the fourth round when she completed a routine 6-1 6-4 win over 26th seeded compatriot Maria Kirilenko.