Defending champion Aryna Sabalenka survived the first test of the Australian Open, but last year's beaten finalist Qinwen Zheng suffered a shock second-round exit.
Chinese star Zheng reached her first Grand Slam here last year before winning Olympic gold and establishing herself as one of the best players in the world.
But she was unstuck against Germany's Laura Siegemund, the 36-year-old better known for her doubles prowess, going down 7-6 (7-3) 6-3.
“I don't think I have much to say because I tried what I can do during this match,” Zheng said. “I feel that maybe today is not my day. There are a lot of details in important points. I didn't make the right choice.”
“I knew I just had to play more than my best tennis,” said Siegemund, who earned her first top 10 win since 2022.
“I didn't have anything to lose so I told myself to let it go. She's an amazing player, she's one of the best players right now. But I know I can play and I just wanted this to be a tough fight.”
Sabalenka was also in trouble at 5-2 in the second set against Spain's Jessica Bouzas Maneiro, but the top seed extended her winning streak at Melbourne Park to 16 matches with a 6-3 7-5 victory.
“I'm super happy to finish this match in a row,” Sabalenka said. “She played amazing tennis, especially in the second set. I'm really happy that I was able to turn that set around.”
Tale of the Tape
The Belarusian will next face the talented young Dane Clara Tausonwho beat Tatjana Maria 6-2 6-2.
Naomi Osaka she has not gone beyond the third round of a Grand Slam since winning her second title in Melbourne in 2021.
But the former world number one made a strong start to the season and followed up her first-round win over Caroline Garcia by seeing off 20th seed Karolina Muchova 1-6 6-1 6-3.
Her draw doesn't get any easier with a former top 10 star and co-star Belinda Bencic further.
The Swiss is returning to Grand Slam tennis after the birth of her daughter Bella last April.
Bencic enjoys the change of routine and says: “We just do more fun things and try to go for a walk or go to the aquarium. I don't think I would have gone to the aquarium before.
“So just as far as family time, it's definitely changed. Different things to do now in terms of preparation, but it's better because I think I'm taking my mind off tennis a little bit.”
A seventeen year old Mirra Andreeva went through an extremely close encounter against Moyuka Uchijima, the 14th seed eventually won 6-4 3-6 7-6 (10-8), while the seventh seed Jessica Pegula saw off Elise Mertens 6-4 6-2.
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