CiCi Bellis was terrified. Surgeons told her that to save her highly promising tennis career they had to break her arm in half. Then, just three months ago, the 20-year-old American was told her career was over because of a new injury.

But on Thursday the world No 600, once a teenage prodigy, shocked the 20th-seeded Karolina Muchova of the Czech Republic to reach the Australian Open third round.

Wearing a bandage on her right wrist and with a significant scar running up the lower part of her arm, the San Francisco native was the focus of intense media interest following her surprise victory.

“A year ago this time I did not even know if I’d play again so just being here is so special to me, let alone winning,” said Bellis, who was touted as a rising star of tennis when at 15 she defeated 12th seed Dominika Cibulkova at the 2014 US Open.

Bellis, who hit a career-high 35 in the world in August 2017, has been through injury hell with tears in her right wrist and fractures to her elbow. The first low point arrived when she was told of the daunting surgery. She has had four operations in all.

“My mum and I were looking at each other and laughing because we had never heard of anything so barbaric in our entire lives,” Bellis said of the moment surgeons told her what they needed to do to save her career.

“He was on the phone telling us that we are going to break your arm in half, shorten it, then put a plate in, then we are going to need to remove the plate.”

‘Worst day ever’

Bellis had been rehabilitating for 18 months when in October she was told she would never play again because of a new injury. This time it was a problem with her elbow. “Thinking back to it now, I should have just laughed because of everything I’d been through,” she said.

“But I was so upset, it was one of the worst days ever. It was just horrible because we had already been through so much together – my family has been going through all the emotions with me.”

The despair was deep, but thankfully short-lived. She was referred to another doctor in the same building the same day.

This one had better news. She had been misdiagnosed and her career was not over. In November she competed in her first professional tournament for 20 months. Now she is at the pinnacle of tennis, pain-free, and faces the Belgian 16th seed Elise Mertens in the third round in Melbourne.

“My love for the game is what really drove me through all this time,” said Bellis, hardly able to keep the smile off her face. It’s definitely going to take some more tournaments to get into the swing again. But each match it’s getting better.”