Li, the defending champion, will next play Annika Beck of Germany. Beck defeated Patricia Mayr-Achleitner of Austria 3-6, 6-3, 6-1.
Also advancing to the semifinals was fifth-seeded Peng Shuai of China. Peng beat Jana Cepelova of Slovakia 6-3, 6-2 and will next face Vania King of the United States. King beat Barbora Zahlavova Strycova of the Czech Republic 6-2, 6-4.