Novak Djokovic, Coco Gauff roll to Australian Open's 4th round. Naomi Osaka retires due to injury and Jessica Pegula was upset in the third round.

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.

It's time for the eighth installment of the riveting, intergenerational rivalry between Novak Djokovic and Carlos Alcaraz. This one, though, will be the first at the Australian Open — and the first in the quarterfinals of a tournament;