World number one Novak Djokovic raced into the second round of the US Open with a demolition of Joao Souza of Brazil. The top seed had to wait in the wings for Venus Williams to complete a two-hour, 40-minute win. But once the Serb hit the court, he sped to a 6-1, 6-1, 6-1 victory in just 1 hour and 11 minutes. Elsewhere, fourth seed Kei Nishikori's hopes of making another magical US Open run have come to a quick end. Last year’s runner-up fell at the first hurdle – in five sets to Frenchman Benoit Paire. Nishikori's run last year included a shock victory over Djokovic. There was a shock result in the ladies draw as well, as former world number one Ana Ivanovic was beaten by Dominika Cibulkova the opening match at the Arthur Ashe Stadium.