Jelena Jankovic makes a poor start in her fourth-round match against rising Danish star Caroline Wozniacki

On another hot day in New York, 18-year-old Wozniacki overpowers the second seed in the first set, taking it 6-3

But the world number two's greater experience tells in the end as she reaches the quarter-finals with a 3-6 6-2 6-1 win

The crowds flock to Arthur Ashe Stadium for a glimpse of four-times defending champion Roger Federer

And they are not disappointed as Federer hits top form to sweep aside tricky Czech opponent Radek Stepanek

Luxembourg qualifier Gilles Muller continues his astonishing run, recovering from two sets down for the second match running

American Andy Roddick makes a good start in his bid to reach the fourth round by taking a two-set lead against Andreas Seppi

Roddick is broken for the only time in the third set but fights back to take it on a tie-break to complete a 6-2 7-5 7-6 win

All smiles for Elena Dementieva as she brushes aside Li Na 6-4 6-1 to book a quarter-final against Patty Schnyder

World number three Novak Djokovic stars in the second match of the night session, up against dangerous Croat Marin Cilic

Cilic, 19, threatens to cause a major upset when he takes the first set against the Australian Open champion

But Djokovic eventually comes through after nearly four hours on court to book a meeting with Tommy Robredo