Top seed Shuai Peng has been dumped out of the Taiwan Open at the first-round stage.
China's world number 31 was beaten 6-4 6-1 by Romanian world number 89 Ana Bogdan, who only faced one break point in the course of a dominant display.
There was another upset as Japan's world number 93 Nao Hibino ousted Australia's third seed Sam Stosur 7-6 (8/6) 6-2 in a match lasting one-and-a-half hours.
Former Wimbledon finalist Eugenie Bouchard battled back from a poor first set to lead Lin Zhu 1-6 7-5 2-0 before her Chinese opponent was forced to retire injured.
Eighth seed Pauline Parmentier was also forced to fight back to overcome Japan's Kurumi Nara 1-6 6-4 6-1.
Seventh seed Magda Linette beat China's Han Xinyun 6-2 6-0, while there were also wins for Wang Yafan, Johanna Larsson and Sabine Lisicki.
In the St Petersburg Ladies' Trophy, fifth seed Julia Goerges battled to a hard-fought 6-2 7-6 (7/5) victory over Greece's Maria Sakkari.
Eighth seed Daria Kasatkina also made it safely through to the second round with a 1-6 6-4 6-1 win over Viktoria Kuzmova of Slovakia.
Dominika Cibulkova beat Sorana Cirstea 7-5 6-2 and other winners were Irina Begu, Vera Zvonareva and qualifiers Roberta Vinci and Elena Rybakina.