World number one and defending champion Novak Djokovic reached the third round of the US Open without swinging his racquet on Wednesday when scheduled opponent Jiri Vesely pulled out injured. Serbia's Djokovic won by walkover when left forearm inflammation prompted Czech Vesely - who inflicted a rare defeat on Djokovic on the claycourts at Monte Carlo in April - to withdraw prior to the afternoon second round clash scheduled for the Arthur Ashe stadium court.