Zhang Shuai is the feel-good story of the Australian Open and even fourth-round opponent Madison Keys can't help but smile.
Chinese qualifier Zhang broke down in tears after shocking Simona Halep in the opening round, revealing she recently contemplated retirement after a horrible run of form.
Zhang had lost all 14 of her previous grand slam matches, dating back to the 2008 US Open.
Since ousting second seed Halep on day two of the event, Zhan has celebrated her 27th birthday and beaten Alize Cornet and Varvara Lepchenko.
She next faces Keys, a highly-rated American who is seeded 15th and progressed to the semi-finals at Melbourne Park in 2015.
"We're so happy for her," Keys said of Zhang's breakthrough performance.
"I haven't played her since three, four years now.
"Obviously she's playing well if she's had the upsets that she's had."
Keys beat Ana Ivanovic 4-6 6-4 6-4 on Saturday night, while world No.133 Zhang crushed Lepchenko 6-1 6-3.
Confidence is building for the woman who invited her parents to Melbourne, expecting the clash with Halep to be her last grand slam match.
"Before, no. But today, maybe yes," Zhang said, when asked if she believed she could win the tournament.
Zhang said she had some confidence from seven wins so far this year, but that before facing Lepchenko, she had thought the match might be her last.
"No more nervous (feelings) for me ... I'm enjoying the tournament," she said.
Zhang has been blown away by her support, particularly the number of Chinese people coming to the games.
"Every time many people watch me play, I play really well."
Zhang revealed 20-year-old Keys wasn't the only player on the WTA tour to offer congratulations and support.
"So many girlfriends come to hug me. So proud of me, so exciting and happy," she said.
"They just tell me 'good luck, keep winning'.
"On the tour, we know each other very much. Very good friends.
"They thought I would not win one match in the grand slam, so I think so many players so happy."
