Melbourne: Novak Djokovic underlined his supremacy in men's tennis on Friday as he marched unstoppably into the Australian Open fourth round along with Serena Williams, who raced through in just 44 minutes.

Novak Djokovic returns to Italy's Andreas Seppi during their Australian Open third round tie in Melbourne yesterday and Serena Williams returns to Russia's Daria Kasatkina in an Australian Open third round match in Melbourne yesterday. Pics/AFP