SHANGHAI, China: World number seven Ons Jabeur defied a bad knee on Thursday to finally defeat Italian Lucia Bronzetti 6-3, 7-6 (7/5) and reach the quarter-finals of the Zhengzhou Open. Playing with her right knee taped, the Tunisian three-time Grand Slam finalist failed to serve out the victory on three occasions and needed five match points to move past the 63rd-ranked Italian in just under two hours. A champion in Ningbo two weeks ago, Jabeur will next face eighth seed Daria Kasatkina, who beat home player Bai Zhuoxuan 6-2, 6-4. “It was a tough finish obviously, she’s a great player, such a fighter,” said the 29-year-old Jabeur. “So, I’m glad that I got to finish in two (sets). It would have been a different story if it was three sets.