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The 18-year-old Czech was impressive against the No.3 seed as she recorded her first win against anyone in the top 30 of the world rankings.
No.4 seed Veronika Kudermetova eased past Amanda Anisimova in just an hour and 15 minutes, winning 6-3 6-0, while Liudmila Samsonova will face No.2 seed Aryna Sabalenka in the next round after coming from a set down to beat Zhang Shuai 5-7 6-3 6-0.
Irina-Camelia Begu and Elena Rybakina also both came from behind to secure wins, with the latter beating No.5 seed Danielle Collins to set up a round of 16 clash against Ukrainian Marta Kostyuk, who beat Jaimee Fourlis 6-1 3-6 6-4.
At the ASB Classic in Auckland, 42-year-old Venus Williams comfortably overcame her 21-year-old opponent Katie Volynets 7-6 (7-4) 6-2, and will play China's Zhu Lin next after she eliminated No.6 seed Madison Brengle 4-6 7-6 (8-6) 6-4.
No.3 seed Leylah Fernandez beat Brenda Fruhvirtova 6-1 6-1 to set up a round of 16 tie with Julia Grabher after she defeated Tereza Martincova in three sets.
No.8 seed Rebecca Marino is through after beating Dalma Galfi in straight sets and will now face Ysaline Bonaventure, who eventually put away Caty McNally 5-7 6-4 6-4.
Viktoria Kuzmova led No.4 seed Bernarda Pera 5-4 in the opening set when rain stopped play for the day.
