Last year's runner-up Zheng Qinwen was knocked out of the Australian Open on Wednesday in the biggest shock so far while defending champion Aryna Sabalenka had to battle serve jitters to make the third round.
Fifth seed Zheng was sent packing 7-6 (7/3), 6-3 on John Cain Arena by world number 97 Laura Siegemund of Germany, the second-oldest player in the draw at age 36.
