Second seed Jelena Jankovic came through another bruising battle at the US Open on Friday, edging past Zheng Jie 7-5, 7-5 to reach the fourth round.
The Serbian, chasing her first grand slam title, scrambled into the last 16 after two hours nine minutes and will meet 14th seed Victoria Azarenka of Belarus or Caroline Wozniacki, the Danish 21st seed.
Having been pushed to three sets in the previous round, Jankovic again became embroiled in a tough encounter as Wimbledon semi-finalist Zheng matched her from the baseline.
World number 37 Zheng saved four match points in a marathon 12th game of the second set which featured 11 deuces but Jankovic finally clinched victory when the Chinese netted a forehand.
(Writing by Simon Cambers, editing by Pritha Sarkar)