Crushing victory for Djokovic
Novak Djokovic continued the dominance of the top seeds in the US Open men's singles with a straight sets win over Joao Sousa.
It took the world No 1 only 28 minutes to wrap up the first set to love, and he went on to win the third-round encounter 6-0 6-2 6-2 in an 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 No 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.
However despite the comprehensive win, Djokovic believes there is still plenty to work on.
"I am not obviously as comfortable on the net as I am on the baseline, but I've been working on it," he said.
"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 serve, especially that part of my game. I want to try and get as many free points on the serve as possible."
There were two minor upsets as Tommy Haas and Andreas Seppi both bowed out.
Haas, the 12th seed, suffered a 6-3 6-2 2-6 6-3 defeat against the No 21-ranked Mikhail Youzhny, while 20th-seeded Seppi lost 6-36-4 2-6 3-6 6-1 to Denis Istomin.
Tomas Berdych set up a fourth-round tie with ninth seed Stanislas Wawrinka after his demolition of Julien Benneteau.
The fifth seed, a potential quarter-final opponent of Andy Murray, raced to a 6-0 6-3 6-2 victory.
Former champion Lleyton Hewitt and Marcel Granollers are also through after they saw off Evgeny Donskoy and Tim Smyczek respectively.