Stanislas Wawrinka has admitted that it was a "big challenge" to overcome the powerful serving of Marius Copil in the Australian Open second round.

The defending champion progressed in straight sets in a match where Copil recorded a 150mph serve, and the Swiss number two has acknowledged that he was happy to avoid getting involved in an extended contest in sweltering conditions in Melbourne.

The 29-year-old told Eurosport: "It was three tough sets. It was much hotter today and he played some really aggressive tennis.

"It was a big challenge. He served very well but I also felt that I served to a high standard too. I did what I had to and in the end, that was enough. I'm satisfied that I didn't lose too much energy out there."

Wawrinka will play Jarkko Nieminen in the last 32 on Saturday.