Second seed Jelena Jankovic battled through a painful knee injury to overcome Danish teenager Caroline Wozniaki 2-6 6-4 6-2 and reach the fourth round at Wimbledon on Saturday.

The Serb slipped and jolted her left knee at the beginning of the match and appeared in trouble when the 17-year-old Wozniaki, seeded 31, capitalised on a string of errors from her opponent to go a set up.

An early break was enough for Jankovic, 23, to square the match before the Serb took a medical timeout to have her swollen left knee heavily strapped. Wincing after almost every point, a hobbling Jankovic broke to lead 3-1 and, playing on without the strapping, she limped to victory.