MELBOURNE - Last year's runner-up Zheng Qinwen was sent crashing out of the Australian Open second round on Wednesday as her bid to emulate Chinese compatriot Li Na's 2014 triumph evaporated after a shock 7-6(3) 6-3 defeat by unseeded German Laura Siegemund.

Zheng, who lost to Aryna Sabalenka in the title decider at Melbourne Park 12 months ago, said she had been bothered by some fitness issues after her run to the final of the WTA season-ending championship in November.

The 22-year-old felt she had not had the ideal build-up to the year's first Grand Slam after having to miss tune-up events.

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"For me, there was no chance to play a tournament before the Australian Open because the time was so rushed," said Zheng.

"I got some small issues after the WTA Finals. I discussed with my team if we have to come to the Australian Open or no.

"I'm the one forcing (them). My team said no. I've got to come here and try to play a slam. That's the tricky situation. There are issues in my body that haven't been solved yet."

The Olympic champion looked out of sorts in the opening match of the day on John Cain Arena as Siegemund came out all guns blazing and rode her luck at times to clinch a tight opening set in the tiebreak.

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"I had lot of chance to break her in the first set, but in that moment maybe my concentration wasn't there," said Zheng. "I made mistakes in those moments.

"It was a bit tricky for me in the first set, a tricky way to lose it, because I didn't perform good enough.

"At the same time, I felt she was playing really good today. Yeah, it's tennis. Nothing more."

An early break in the next set handed the 36-year-old German the advantage and although fifth seed Zheng fought back with one of her own, she quickly found herself 3-1 down.

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World number 97 Siegemund delivered the final blow on serve and dropped to the floor with her hands covering her face while Zheng left the court shortly afterwards, looking like she was ready to burst into tears.

"I knew I just had to play more than my best tennis," said Siegemund, who earned her first top 10 win since 2022.

"I had nothing to lose so I told myself to swing free. She's an amazing player, she's one of the best players now. But I know I can play and I just wanted to make it a tough fight."

Siegemund, the second oldest woman in the draw, takes on Anastasia Pavlyuchenkova or Anastasia Potapova next.