China’s eighth seed Peng Shuai upset the rankings to defeat fourth-seeded American Sloane Stephens, 6-2, 6-3 on Thursday to reach the Brussels Open quarter-finals. Peng is now through to the seventh Premier-level semi-final of her career, having gone 1-5 in her previous six. However, she did make the final in the Belgian capital in 2011 where she lost to former world number one Caroline Wozniacki. “It was cold out there but I had a good start, probably because I played so much yesterday,” said Peng, who played twice on Wednesday at this rain-hit claycourt event. “Two years ago I made the final so I always feel really good here, and now I’m in the semi-finals again,” Peng said. “I’ll keep fighting in the next match and hopefully I can make the final again.” Zheng Jie was unable to make it a China one-two after she went down 6-3, 3-6, 6-0 to Italy’s Romina Oprandi. Peng and Oprandi will now square off in the semi-finals, with their head-to-head series tied at 1-1. “We just played a few weeks ago in Portugal and it was a really tough match for me,” Peng said. “She played so many drop shots and they worked so well on the clay. She beat me really easily that day.” The other two quarter-final matches, pitting Roberta Vinci against Jamie Hampton Varvara Lepchenko against Kaia Kanepi, were pushed back to Friday.