Ninth-seeded Ana Ivanovic, who won the Pan Pacific Open in Tokyo over the weekend, was among the four seeded players who crashed out of the Wuhan Open.
Ivanovic retired with a thigh problem when her opponent Anastasia Pavlyuchenkova was serving for the match at 7-5, 6-5.
Meanwhile, Caroline Garcia followed up her first-round win over Venus Williams with a 3-6, 7-6, 7-6 upset win over fifth seeded Agnieszka Radwanska.
The 20-year-old Frenchwoman went for broke, continuing to hit big ground strokes despite piling up unforced errors as she tried to keep Radwanska on the back foot.
Elsewhere, Jelena Jankovic beat Christina McHale 6-4, 6-4 and Sara Errani of Italy reeled off the last six games to beat Heather Watson of Britain 7-5, 6-4.
Sabine Lisicki beat Lucie Safarova 7-5, 2-6, 6-3 and Australian qualifier Jarmila Gajdosova ousted Flavia Pennetta 6-1, 6-4.
Wuhan is one of three new WTA-level tournaments added in China this year, along with Hong Kong and Tianjin. The newcomers bring the total number of tournaments in China to six - behind only the United States, which has eight.