Federer received a warning and was surprised and demanded to know what he was doing.

"What did I say?" Federer asked.

"I can't repeat that, Roger, I heard about what you said, but she (pointing to the line judge) clearly heard," the chief judge told the Swiss.

At the press conference after the match, which Federer miraculously turned and won, he had to explain what happened at the warning.

- It is natural to feel a little frustrated after 15 hours out on the track. I'm not known for screaming things, so I thought it felt pretty hard. But I have to accept it.

But was it in English you swore?

- It was a mixed language. She apparently talks mixed, Federer laughs.

- I'll take the line judges next time ...

See what happened in the clip above