Alicia Molik continued her remarkable run at the Australian Open, booking a last-16 spot at the expense of fellow surprise package Claudine Schaul.
Molik, who beat Daniela Hantuchova in the previous round, battled back from the loss of the first set to beat Schaul 6-7 (4-7) 6-1 6-2.
Luxemburg's Schaul accounted for Elena Bovina in the third round but faded quickly against Molik.
Molik goes on to face one of the tournament favourites, Amelie Mauresmo.
Mauresmo defeated Anabel Medina Garrigues of Spain 6-1 6-2, despite an injury scare.
Russia's Vera Zvonareva ended the hopes of Australia's only other remaining representative in the women's draw with a battling 7-5 2-6 6-1 winover Nicole Pratt.
The 11th seed now faces fifth seed Lindsay Davenport, who easily defeated fellow American Laura Granville 6-4 6-0
Elsewhere 32nd seed Fabiola Zuluaga edged out Jill Craybas 7-6 (7-5) 4-6 6-2.
Hungary's Aniko Kapros survived a tense encounter with compatriot Petra Mandula , eventually triumphing 3-6 6-3 12-10.
And Italy's Mara Santangelo caused the suprise of the day by ousting 19th seed Eleni Daniilidou 6-4 5-7 6-3.