A bad bout of asthma nearly derailed the comeback of former world No 2 Ons Jabeur at the Australian Open on Thursday, with the Tunisian saying she found it hard to breathe and nearly gave up in her second-round victory.

The 30-year-old three-time Grand Slam finalist is aiming to get back to the top after a shoulder injury last year threatened her career.

But she said asthma was now becoming an issue.

Jabeur, ranked 39, needed a medical timeout on her way to a 7-5, 6-3 victory over Colombia's Camila Osorio for treatment and to use an inhaler.

"Very, very tough to breathe. When I was younger, I was diagnosed with asthma," she said, adding that she may not have continued if she had lost the first set.

"It is very tough to play. I had to kind of not play long rallies.

"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 to behave like this on the court."

Jabeur said she doesn't usually talk about her asthma problem.

"We will have to manage, you know, like we always do," she said.

"I think I will have to find a way to feel better the next two days, which I am hoping to do because this started kind of two days or three days ago. I feel like it got worse for some reason.

"I'm really just taking it one minute at a time and see how it's going to go, but definitely I'm doing everything that I can to be ready."

She faces a tough third-round clash against American eighth seed Emma Navarro, who came back from the brink to beat China's 108th-ranked Wang Xiyu in three sets.

Jabeur won their only previous meeting, 6-3, 6-2, on clay in Navarro's hometown of Charleston in 2022.

AFP