MELBOURNE: Naomi Osaka said it "took everything" to battle from a set down to win her second-round match against world No.20 Karolína Muchová.
The two-time Australian Open champion took revenge on Muchová who had defeated her in the US Open last year.
It's the first the Japanese star she will enter the third round since giving birth to her daughter Shai.
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Naomi Osaka of Japan reacts after winning a point against Karolina Muchova of the Czech Republic during their second round match at the Australian Open tennis championship in Melbourne, Australia, Wednesday, Jan. 15, 2025. (AP Photo/Asanka Brendon Ratnayake) AP
"It honestly took everything and I left everything on the court," Osaka said.
"Last year was really tough for me and I thought I could have done better but to be back playing on these courts makes my whole year.
"I am happy to play another round."
Osaka had a shaky start to her match on Kia Arena, dropping the first set 1-6.
However, she remained composed as she entered the second set, and it was clear she was gaining confidence, hitting 13 winners and two aces.
Muchová had no answers for the Japanese star and struggled with her serve, winning just 25 per cent of her first serve points with only 43 per cent accuracy.
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Osaka continued to build momentum as she entered the third set, and after seizing control, she needed just one match point to close it out.
Muchová had won their last two meetings, and Osaka conceded post-match that the Czech player was an incredibly tough competitor.
"It means a lot, she's an incredibly difficult opponent to play," the four-time slam winner said.
"She crushed me in the US Open. This was my little revenge.
"It's not a bad thing but it means a lot because she is one of the toughest opponents out there."
The match had far less controversy than her opening-round win over close friend Caroline Garcia at Rod Laver Arena on Monday.
Osaka was left stunned when the electronic line calling system didn't trigger, and a ball that appeared out was called in.
She remained calm following the call, and went on to win 6-3, 3-6, 6-3.
Osaka will face former world No.4 Belinda Bencic on Friday, who leads their head-to-head meetings 3-2.
