Second seed Jelena Jankovic [ Images ] came through another bruising battle at the US Open [ Images ] on Friday, edging past Zheng Jie [ Images ] 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 [ Images ] of Belarus or Caroline Wozniacki [ Images ], the Danish 21st seed.

• Coverage: US Open 2008

Having been pushed to three sets in the previous round, Jankovic again became embroiled in a tough encounter as Wimbledon [ Images ] 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 [ Images ])