Summary:
Novak Djokovic says he is "very happy" with his run of form at the U.S. Open after a battling third-round win over Rogerio Dutra Silva.

Full article:
(CNN) -- Defending champion Novak Djokovic dropped just five games as he progressed to the third round of the U.S. Open on Friday. The Serb needed only one hour and 39 minutes on court to see off Brazil's Rogerio Dutra Silva in straight sets (6-2 6-1 6-2), but said the scoreline didn't reflect the battle. "It was very windy so it was very important to stay focused, but I played great. Even if the scoreline doesn't indicate it, it was a tough match," Djokovic said. "It's important to get a day's rest and work on some things in my game and get ready for the next challenge," Djokovic added. That next challenge is likely to be 31st seed Julien Benneteau of France who plays U.S. teenager Dennis Novikov later on Friday. Benneteau's compatriot Richard Gasquet also coasted through his second round match beating America's Bradley Klahn 6-3 6-3 6-1. Earlier, America's Steve Johnson booked his place in the third round with a four-set (6-7 7-6 6-3 6-4) win over Latvia's Ernests Gulbris, as did fourth seed David Ferrer. The Spaniard, a semi-finalist at Flushing Meadows back in 2007, was a comfortable 6-2 6-3 7-6 (14-12) winner over Dutch qualifier Igor Sijsling. Andy Roddick will be looking to delay his impending retirement when he plays Australia's Bernard Tomic later on Friday.