Ons Jabeur revealed that she was struggling to breathe as she overcame Colombian Maria Camila Osorio 7-5, 6-3.

The Tunisian star needed to take a medical time out after an asthma attack in the Melbourne heat, adjusting her playstyle as a result.

“It ws very, very tough to breathe," she said. "When I was younger, I was diagnosed with asthma. It is very tough to play. I had to kind of not play long rallies.

"I know I was playing Camila today. Not the best opponent when you are in this condition, but I apologized at the end of the match, because I really don't want behave like this on the court. I used the inhaler when I took the medical timeout. It didn't really help.

"So I was with the doctor, and let's see. We're going to do some more tests and see what's going on. To be honest with you, if I lost the first set, it would have been very difficult to continue.”