Zhang Shuai’s miracle run at the Australian Open continued with yet another emotional victory for the Chinese world No133, but it also meant heartbreak for 2015 semi-finalist Madison Keys who left the court injured and in tears.

The 27-year-old Zhang, who came to Melbourne with zero wins in 14 grand slam appearances but has now made her way into the quarter-finals, held her nerve to beat the No15 seed 3-6, 6-3, 6-3 while watching Keys suffer from an abductor injury.

Zhang considered retirement just three months ago and brought her parents to Australia thinking it may be their last chance to see her compete. She says she would have liked to open her own “coffee bar” had she left the sport. But since she got to Melbourne, she has won seven matches – three in qualifying and four in the main draw – and now finds herself one of the last eight remaining players in the draw.

Her win over Keys means she is the first qualifier to reach the quarter-finals in Melbourne since Mexico’s Angelica Gavaldon in 1990, and she now has a chance to go further should she overcome Johanna Konta.

“I’m very excited. Very happy. I don’t want to stop. I want more steps,” said Zhang, who looked too exhausted to form complete sentences in the press conference.

“It’s so tough to play against someone injured because I saw her feel more pain. You know, it was so tough. Maybe two points you feel like you cannot play, and then next three balls, pong, pong, pong, make two aces, one winner.

“So, so tough. You don’t know what’s happened. And also last year this happened many times. I’m almost winning the match. I lost. I lost the concentration. But this time I think I try to concentrate.”

Keys, who was barely able to move after the match and couldn’t make her way to the interview room, says she felt like she tore her adductor towards the end of the first set but wanted to keep on fighting.

“One I hate retiring, and two, you don’t want to do that to someone who is trying to get into the quarter-finals,” said a tearful Keys, speaking in the media restaurant. “I thought maybe I could figure it out and somehow get through then have a day off and try but, obviously, not going to happen.”

Asked how disappointed she was, Keys said: “I don’t think there’s a word for it.”

As a qualifier, Zhang has already had an incredibly long two weeks in Melbourne and convinced herself that Monday was a final to find some strength.

“I’m thinking ‘today is the final’. When somebody already wins six matches at a grand slam, already it’s the final, right?” she said.