Naomi Osaka, a two-time champion in Australia, stopped playing because of a strained abdominal muscle after dropping the first set of her match against Tokyo Olympics gold medalist Belinda Bencic.

In a tougher-than-expected match, Aryna Sabalenka beat Clara Tauson 7-6 (5), 6-4 in a poor serving display by both players to open the sixth day of play on Rod Laver Arena.

Defending champion Aryna Sabalenka was pushed to the limit while Carlos Alcaraz dropped a set before surging into the last 16.