Defending champion Aryna Sabalenka knocks out teenager Mirra Andreeva on Rod Laver Arena; Coco Gauff battles back to set up showdown with Spaniard Paula Badosa; watch all the action from the ATP and WTA Tours on Sky Sports Tennis and Sky Sports+,

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.

With a 6-1, 6-2 victory over 14th-seeded Mirra Andreeva to open play Sunday at Rod Laver Arena, Aryna Sabalenka advanced to the quarterfinals of the Australian Open, where she's three wins from achieving something no woman has done since the 1990s.