WTA roundup: Teen topples Naomi Osaka in Tokyo

September 1, 2026; New York, United States; Japan's Naomi Osaka reacts during her first round match against Russia's Anastasia Zakharova. Mandatory Credit: Robert Deutsch-Imagn Images Slovakian teenager Mia Pohankova knocked out former champion Naomi Osaka in straight sets Thursday to advance to the quarterfinals of the Toray Pan Pacific Open in Tokyo. The 18-year-old upstart defeated the seventh-seeded Japanese star 6-3, 7-5 in 95 minutes for the biggest win of her career. Ranked No. 659 at this time last year, Pohankova kept her cool and saved two break points in the second set before breaking Osaka to end the match. Pohankova will face Alycia Parks, a 6-3, 6-1 winner over Australia's Kimberly Birrell. World No. 1 and top seed Elena Rybakina moved into the quarterfinals with a 6-2, 6-3 win over Kazakhstan compatriot Yulia Putintseva. She will meet Canada's Leylah Fernandez, who posted a 6-2, 7-6 (8) win over No. 5 Elise Mertens of Belgium. Guangzhou Open No. 4 Lilli Tagger of Austria was the only seeded player to survive the day in China, moving into the quarterfinals of the WTA 250 event with a 6-2, 6-2 win over Poland's Magda Linette in just 67 minutes. Two other top seeds fell in three-set matches. China's Xinran Sun outlasted No. 7 Maria Timofeeva of Uzbekistan 6-3, 4-6, 7-6 (3) and Switzerland's Jil Teichmann rallied past No. 6 Zeynep Sonmez of Turkey 4-6, 6-3, 6-1. Also advancing to the final eight were Spain's Kaitlin Quevedo with a 7-5, 6-3 defeat of Hungary's Anna Bondar, and Claire Liu via walkover against Czech Katerina Siniakova. --Field Level Media