GUANGZHOU, China -- Fourth-seeded Urszula Radwanska of Poland knocked out defending champion Chanelle Scheepers of South Africa 6-1, 7-5 Thursday to reach the semifinals of the Guangzhou Open.

Radwanska, who lost to Scheepers in the quarterfinals last year, will next play Hsieh Su-wei of Taiwan, who routed Mathilde Johansson of France 6-3, 6-0.  
Third-seeded Sorana Cirstea of Romania also advanced, beating No. 8 Alize Cornet of France 6-4, 6-3 to set up a semifinal against Laura Robson of Britain.  
Robson overcame Peng Shuai of China 7-5, 5-7, 6-2 in a match lasting more than three hours.