Russian third seed Daniil Medvedev survived a scare as he fought back from a set down before his opponent Terence Atmane quit in tears because of cramp in the Australian Open first round.

Qualifier Atmane won the opening set before Medvedev - runner-up in 2021 and 2022 - turned the match around.

Medvedev led 5-7 6-2 6-4 1-0 when the Frenchman was forced to retire.

"I've cramped like that many times. If he plays like this he can do big things," Medvedev, 27, said.

The conditions in Melbourne on the second day's play were hotter than they have been over the past week, with outside temperatures reaching 27C and increasing further in direct sunlight on court.

Atmane appeared to pull up with cramp in the third set and, after initially carrying on, decided he could not continue after being broken early in the fourth.

The 22-year-old looked close to tears when he shook hands with Medvedev at the net and then sobbed as he hid his head underneath his towel.

Clasping his hands together in a prayer sign, he gave a heartfelt thanks to the crowd for their well-wishes as he walked off.

"It was brutal conditions. What's brutal is it hasn't been hot for seven day here and now it is hot," said Medvedev.

"I regained the momentum and when I started feeling tough, he started cramping.

"I get tired physically, but I know the other guy will tire physically too and see if the other can handle it better."