US Open 2013: Novak Djokovic completes crushing win over Joao Sousa

The world number one eases into week two

Novak Djokovic continued the dominance of the top seeds in the men's singles with a crushing win over Portugal's Joao Sousa in the third round of the US Open.

Andy Murray is the only one of the big four to drop a set so far and, after Roger Federer allowed Adrian Mannarino just five games on Saturday night, Djokovic was even more emphatic.

It took the world number one only 28 minutes to wrap up the first set to love, and he went on to win 6-0 6-2 6-2 in and hour and 40 minutes.

Sousa made his main-draw debut in New York this year and was through to the third round of a grand slam for the first time.

But it had had cost him a lot of effort to get there, with five-set victories over Grigor Dimitrov and Jarkko Nieminen in the first two rounds.

The world number 95 took a medical timeout at the end of the opening set to have his left thigh massaged, and he at last managed to get on the board in the eighth game of the match.

That was an effort in itself, though, and his serve was broken again in the sixth game of the set.

Djokovic then cruised through the first five games of set three before a last hurrah from Sousa.

The Portuguese held his serve and then earned huge cheers from the night-session crowd for a first break of the match only to have his own serve broken to love to end the match.

Djokovic has been working hard on bringing extra variety to his game and added Ivan Lendl's former coach Wojtek Fibak to his team before the start of the tournament.

The Serb, who will play Spain's Marcel Granollers in the last 16, said: "I am not obviously as comfortable at the net as I am on the baseline, but I've been working on it. It's part of my game that I still need to improve. I'm aware of that.

"It makes me happy that I have room for improvement, and I keep on spending hours and hours on the court and working on variety in my game.

"And the serve, especially that part of my game. I want to try and get as many free points on the serve as possible."