China's Qinwen Zheng recorded a 6-3, 6-2 victory over top-seeded Paula Badosa of Spain on Wednesday in the second round of the Toray Pan Pacific Open in Tokyo.
Zheng, 19, completed the upset in 78 minutes after winning 11 of the last 13 games to set up a quarterfinal clash against Claire Liu, who posted a 6-4, 6-1 win over Elise Mertens of Belgium.
Shuai Zhang of China also notched an upset on Wednesday with a 4-6, 7-6 (5), 7-6 (5) victory over second-seeded Caroline Garcia of France.
Luidmila Samsonova of Russia posted a win over Wimbledon champion Elena Rybakina of Kazakhstan, while third-seeded Garbine Muguruza of Spain polished off a 6-4, 6-2 victory over Greek qualifier Despina Papamichail.
--Hana Bank Korea Open
Second-seeded Ekaterina Alexandrova breezed to a 6-1, 6-3 win over home-country favorite Na-Lae Han during a second-round match in Seoul.
Alexandrova recorded three aces and overcame four double faults to end the match in 62 minutes.
Like Alexandrova, fourth-seeded Lin Zhu of China, sixth-seeded Emma Raducanu of Great Britain and seventh-seeded Tatjana Maria of Germany secured straight-set wins. Zhu posted a 6-1, 6-3 victory over Ankita Raina of India, Raducanu seized a 6-2, 6-4 triumph over Japan's Moyuka Uchijima and Maria cruised to a 6-0, 6-3 win over Australian Kimberly Birrell.
Eighth-seeded Canadian Rebecca Marino was not as fortunate. Andorra's Victoria Jimenez Kasintseva took down Marino 6-4, 6-2.
--Field Level Media