Reigning Guangzhou Open champion Lesia Tsurenko's title defence was halted at the first hurdle by Aleksandra Krunic.
The Ukrainian fell to a 6-3 6-4 loss on Monday, which also saw the surprise defeat of Alison Riske.
World number 226 Rebecca Peterson produced a shock to knock out the eighth seed.
The Swede put on a superb display to triumph 6-3 6-2 against a player ranked 177 places above her.
Anett Kontaveit refused to fall victim to the curse of the seeds, seeing off Jasmine Paolini 6-0 6-2, while Yanina Wickmayer won two tie-breaks to defeat Lesley Kerkhove.
Patricia Maria Tig's retirement saw Danka Kovinic progress, while Kateryna Kozlova downed home hope Liu Fangzhou 7-5 6-0.
Elsewhere in the draw, qualifier Ipek Soylu overcome Maria Sakkari 6-0 6-3 and Mona Barthel was a 6-0 4-6 6-3 victor over Lu Jingjing.