Novak Djokovic wasted little time in following his fellow top seeds into the the fourth round at the US Open with a crushing win over Portugal's Joao Sousa at Flushing Meadows.
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 No1 only 28 minutes to wrap up the first set to love, and he went on to win 6-0, 6-2, 6-2 in just one 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.
Rally and shot of 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."
Meanwhile, defending champion Andy Murray also eased through to the last 32 with a straight sets win over German Florian Mayer.
The Scot, destined to meet close friend and rival Djokovic in the semi-finals, admitted afterwards he had struggled with his breathing in very humid conditions in New York.
Murray was only on court for a minute under two hours but looked drained as he finished off a 7-6 (7/2) 6-2 6-2 victory.
The world No3 said: "It was tough conditions. It was very, very humid. With the way that he plays, it was a tough match, especially the beginning.
"But I started the second set well. I started hitting the ball a little bit cleaner, was more aggressive after that, and finished it well. "I was struggling breathing for most of the match."
Meanwhile, Tomas Berdych and Stanislas Wawrinka set-up a US Open last-16 clash.
Fifth seed Berdych, who defeated Federer on his way to the semi-finals last year, eased past French 31st seed Julien Benneteau 6-0, 6-3, 6-2.
Swiss ninth seed Wawrinka got past unseeded Cypriot Marcos Baghdatis, the former world No8 but now down at 53 in the world, 6-3, 6-2, 6-7 (1/7), 7-6 (9/7).
In the ladies draw, Serena Williams won the battle of the Americans as she saw off young pretender Sloane Stephens 6-4, 6-1, while La Na continued her impressive form by seeing off former world No1 Jelena Jankovic 6-3, 6-0.
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