World number one Novak Djokovic made a dominant start to his US Open campaign by easing to a straight-sets victory over Joao Souza.

The 28-year-old, who won his only previous title at Flushing Meadows in 2011, needed just one hour and 13 minutes to earn a 6-1 6-1 6-1 win over the Brazilian.

The Serb began the match strongly and forced his opponent into a number of errors, before making a crucial break in the fourth game of the opening set.

Souza was quickly broken again, and Djokovic held onto his serve to comfortably take the first set in 24 minutes.

The second set followed in the same pattern, with Djokovic producing another powerful display to break Souza three times on the way to another 6-1 win.

Souza made a bright start to the final set, but despite his best efforts, he was unable to deal with the class of his opponent, as Djokovic saw out the match to book his place in the second round.