Zhang Shuai nearly quit tennis last year when she couldn't win a match and her ranking plummeted from inside the top 50 on the WTA Tour.
The Chinese qualifier beat No. 2-ranked Simona Halep 6-4, 6-3 on Tuesday for her first main-draw win at any Grand Slam tournament after 14 losses.
It was the most first-round defeats with no wins for any player in the top 300 in the rankings.
''I played really well today ... against a great player,'' Zhang said.
And it helped restore some confidence.
''The last few months, I'm already 200, my ranking, so very tough,'' she said. ''I feeling very sad every day. I almost retired.
''But so many people help me, so give me the help. My coach, my parents, my team, also national team. My sponsor, always try to help me, give me more motivation. So I'm training hard, more hard than before.''
The No. 133-ranked Zhang, who won three matches in qualifying, will next play Alize Cornet, who beat Bojana Jovanovski 6-1, 6-0 Tuesday.
