Top seed Marion Bartoli retired from her first-round match at the $220,000 Guangzhou International tennis event due to a gastrointestinal illness.
The French former Wimbledon runner-up Bartoli was trailing Taiwan's Kai-Chen Chang 4-3 when she decided to stop on the hardcourts at Tianhe Sports Centre.
Three other top-four seeds advanced, as No. 2 Chinese Zheng Jie defeated Taiwanese Yung-Jan Chan 5-3, retired, No. 3 Romanian Sorana Cirstea handled Chinese qualifier Hu Yue-Yue 6-2, 7-5, and No. 4 Pole Urszula Radwanska topped Hungarian Melinda Czink 7-6 (7-1), 6-2 on Day 2.
In other opening-round action involving seeds, France's Mathilde Johansson upended No. 6 Romanian Monica Niculescu 7-5, 6-2, No. 7 Chinese Peng Shuai dismissed Japanese Ayumi Morita 7-6 (7-3), 6-0, and No. 8 Frenchwoman Alize Cornet drove out Russian Alexandra Panova 6-3, 1-1, as Panova quit due to a heat-related illness. Peng titled here back in 2008.
Additional wins came for Belarusian Olga Govortsova, Chinese wild cards Duan Ying-Ying and Zheng Saisai, Taiwan's Su-Wei Hsieh, and Thai qualifier Nudnida Luangnam, who bested 2010 Guangzhou champ Jarmila Gajdosova of Australia 6-7 (5-7), 6-4, 6-2.
On Wednesday, Zheng will face rising British left-hander Laura Robson, while fifth-seeded and defending champion Chanelle Scheepers of South Africa will meet Serb Bojana Jovanovski. Scheepers captured her maiden WTA title last year, beating Slovak Magdalena Rybarikova in the final.
The 2012 Guangzhou winner will claim a first prize of $37,000.