Andy Murray dropped a set but still lodged a 7-5 6-1 3-6 6-1 victory over the Argentine slugger Leonardo Mayer to advance to the third round of the US Open on Friday.

The number three seed has become such a drawcard at Flushing Meadows that the queue for his clash stretched hundreds of metres back to Arthur Ashe Stadium.

Mayer's aggression paid dividends in the third set before Murray knuckled down in a blistering fourth set to close out the win in two hours and 41 minutes.

"I was a bit frustrated at points in the match because I was doing quite a lot of the running," Murray said.

"I wasn't getting much depth on my returns.I served a low percentage today. You don't feel like you're dictating the match. It can be frustrating, but I finished the match well.

"I played well when I needed to.That's a good sign. I want to keep improving as the tournament goes on. You don't want to play your best right at the beginning."

"I was a bit frustrated at points in the match because I was doing quite a lot of the running" - Andy Murray

Murray's first serve was poor. He landed a mere 57 per cent of his first deliveries but his renowned fitness and defensive capabilities kept Mayer at bay in an arena that descended into organised chaos at times.

Spectators were late to their seats and called out between points on a court that has been home to numerous close struggles for Murray in recent years.

"It's a court I haven't played my best tennis on, that's for sure," he said. "I've had some tough matches there in the past, and today was the same.

"But I'm happy to play on any court. It doesn't really make a huge, huge difference. We got a great crowd out there.

"It was a really good atmosphere from pretty much the first point through to the last. Whether or not I play well on that court, it's always a really good atmosphere."

His next match will be against another Mayer, Germany's unconventional Florian. They have met twice, on European clay, and Murray has prevailed on both occasions.