Maria Sharapova survived a scare to reach the Australian Open third round as the temperature exceeded 40C for the third consecutive day in Melbourne.
The 2008 champion edged a punishing encounter against Karin Knapp as both players struggled with the heat, which halted play on outside courts.
Sharapova, 26, squandered three match points but eventually won 6-3, 4-6 and 10-8.
Top seed Rafa Nadal and Roger Federer cruised through their second-round matches, both winning in straight sets.
In the men’s doubles, Briton Jamie Murray and Australian John Peers progressed to the second round.