She’s known as Coco to everyone, from tennis diehards to casual sports fans to those who have never sat through an entire tennis match. Now, Cori Gauff can be called a WTA champion.

After losing in the qualifying draw of the Upper Austria Ladies Linz indoor tournament, the 15-year-old American took full advantage of her free pass into the main draw, given when Maria Sakkari withdrew with injury.

Gauff did Sakkari proud, winning five matches at the International-level tournament in Austria, including a quarterfinal over top seed Kiki Bertens, a semifinal over former Top 10 player Andrea Petkovic and, on Sunday, a final over 2017 French Open champion Jelena Ostapenko.

Even more improbable than her run from the outhouse to the penthouse was Gauff’s position in the third set. After winning the first set but quickly dropping the second, Gauff took a 5-0 lead over the talented but erratic Latvian. She then earned two match points on Ostapenko’s shaky serve.

“She’s gotten a little reactive,” said Tennis Channel commentator Lindsay Davenport (a former Linz champion herself), at this critical juncture of the match.

But—finally—nerves and Ostapenko conspired to throw one last obstacle at Gauff, who didn’t convert either match point and was promptly broken at love.

On the 5-2 changeover, Gauff’s dad implored his daughter to target Ostapenko’s backhand. She did, and she earned her third championship point.

The third time was a charm, and you get the feeling there will be many other firsts for Gauff to come.

“I want to thank God for always supporting me,” Gauff said in her on-court championship speech. “I’ll definitely remember this moment for the rest of my life.”