Serena Williams and Naomi Osaka battle through to Australian Open quarter-finals

Serena Williams battled through in Melbourne (Hamish Blair/AP)

Serena Williams and Naomi Osaka both survived close battles to reach the quarter-finals of the Australian Open while Simona Halep gained revenge on Iga Swiatek.

Third seed and title favourite Osaka saved two match points on her way to a 4-6 6-4 7-5 victory over last year’s runner-up Garbine Muguruza before Williams battled to a 6-4 2-6 6-4 win against Aryna Sabalenka.