Djokovic steps up challenge

Novak Djokovic kept alive his hopes of ending Roger Federer’s dominance at the US Open in New York as the third-seeded Serb edged past Radek Stepanek of the Czech Republic.

In an epic, four-hour and 44-minute battle of nerves, the man who beat both Rafael Nadal and Federer en route to winning the ATP Masters Series in Montreal three weeks ago needed a fifth-set tie-break to finally put daylight between himself and the world number 35.