American Amanda Anisimova upset defending Australian Open champion Naomi Osaka on Friday in a thrilling three-set match.

The 20-year-old Anisimova beat the two-time Australian Open winner 4-6, 6-4, 7-6 (5) to capture one of the biggest wins of her career. She came into the tournament ranked 60th in the world.

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Naomi Osaka of Japan reacts during her third-round match against Amanda Anisimova of the U.S. at the Australian Open tennis championships in Melbourne, Australia, Friday, Jan. 21, 2022.

Naomi Osaka of Japan reacts during her third-round match against Amanda Anisimova of the U.S. at the Australian Open tennis championships in Melbourne, Australia, Friday, Jan. 21, 2022. (AP Photo/Simon Baker)

"I knew I had to be playing sharp if I wanted to give myself a chance," Anisimova said after the match.

Anisimova dug herself a hole after the first set but managed to bounce back in the second and play as well as she could to edge out Osaka in the third. She saved two match points in the third set, serving to stay in the match and ending with an ace.

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She had 46 winners compared to Osaka’s 21.

Amanda Anisimova of the U.S. celebrates after defeating Naomi Osaka of Japan in their third-round match at the Australian Open tennis championships in Melbourne, Australia, Friday, Jan. 21, 2022.

Amanda Anisimova of the U.S. celebrates after defeating Naomi Osaka of Japan in their third-round match at the Australian Open tennis championships in Melbourne, Australia, Friday, Jan. 21, 2022. (AP Photo/Simon Baker)

Anisimova had previously beaten Olympic champion Belinda Bencic in the second round.

The Freehold Township, New Jersey, native is into the fourth round, where she will face the top-seeded Ash Barty. Anisimova made it to the fourth round in 2019 as well.

Amanda Anisimova of the U.S. celebrates after defeating Naomi Osaka of Japan in their third-round match at the Australian Open tennis championships in Melbourne, Australia, Friday, Jan. 21, 2022.

Amanda Anisimova of the U.S. celebrates after defeating Naomi Osaka of Japan in their third-round match at the Australian Open tennis championships in Melbourne, Australia, Friday, Jan. 21, 2022. (AP Photo/Simon Baker)

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Barty is one of the top tennis players in the sport. But in one of the biggest tournaments of the season in front of her home crowd, she’s come up short in the last three years. She’s never won the Australian Open.

The Associated Press contributed to this report.