Naomi Osaka smashed her racket into the court after losing the first set. She tumbled to the court when she tripped in the second.

The U.S. Open champion recovered both times and avoided slipping out of the Australian Open on Saturday with a 5-7, 6-4, 6-1 third-round win over Hsieh Su-wei.

The fourth-seeded Osaka got a warning from the umpire after she spiked her racket in frustration when Hsieh took the first set with three breaks of service. To get her mind back on track, she had to pretend like it didnt happen.

The 33-year-old Hsieh, who plays with a double-handed grip on both sides and uses a mixture of spin and slice and drop shots to unsettle her rivals, has taken some top 10 players out of majors before. She reached the fourth round last year here, after beating Garbine Muguruza, and at Wimbledon, where she beat top-ranked Simona Halep.

The 21-year-old Osaka was getting flustered, unable to dictate rallies and seemingly unable to find a way to deal with Hsiehs unusual style.

She found a way back, though, from 4-2 down in the second set when Hsieh was one point away from a 5-2 lead.

Osaka got the important break, rallying from 0-40 to win five straight points and converting it with a deep, powerful backhand that Hsieh barely retrieved but cant keep in play.

Anything that I can do to stay here a bit longer, I tried to do, said Osaka, whod never been past the fourth round of a major before last years U.S. Open, where she beat Serena Williams in the final.

Asked how she managed to get herself back into the contest against Hsieh, Osaka smiled and said it was simple.

I have fun every time I play, she said, even if sometimes it doesnt seem apparent. She quickly reminded the crowd- You guys didnt see me slam my racket, thats not something that I did!

Svitolina beats Zhang

Sixth-seeded Elina Svitolina had her share of trouble, too. She needed treatment on her right shoulder from the trainer and a medical timeout in the second set and had to rally from 3-0 down in the third set before fending off Zhang Shuai 4-6, 6-4, 7-5 in a match lasting almost three hours.

Zhang, who reached the quarterfinals here in 2016 when she was ranked No. 133, needed a medical timeout in the third set but stayed in the contest to the end. She managed to convert a break when Svitolina was serving for the match, and then saved a match point in the last game before netting a tired backhand to finish it.

It was very, very tough match for both of us. She played unbelievable tennis,Svitolina said. I was ... struggling. I just told myself, Im going to die or win.

It was just a mental game I had to stay very strong. We were fighting to the very last point.

She will next play either No. 17-seeded Madison Keys or No. 12 Elise Mertens in the fourth round.

Serena Williams will continue her bid for an eighth Australian title and an Open-era record 24th Grand Slam singles title overall when she plays Dayana Yastremska later Saturday on Rod Laver Arena. A win for Williams on day six of the tournament will set up a fourth-round match against either her older sister, Venus, or top-ranked Halep.