Andy Murray has insisted he has no expectations for the US Open despite getting off to a winning start.

The former world number one stepped out on a Grand Slam match court for the first time since Wimbledon last summer following hip surgery in January and battled to a 6-7 (5/7) 6-3 7-5 6-3 victory over Australia's James Duckworth.

Murray said before the tournament that he should not be considered a title contender, and nothing is about to change his mind.

"(To be a contender) I would have been able to train and practise a lot more than what I have done," he said after Monday night's win.

"I would have played more matches in the build-up to the tournament. There's many, many things that I would have wanted to change to be considered a contender.

"I don't think anything changes after today. I'm still just taking it one match at a time.

"This is the first time I have played four sets in 14 months, so I just have to wait and see how I pull up tomorrow.

"Hopefully I feel good, and take it from there."

After dropping the first set on a tie-break, Murray gradually began to take control against Duckworth.

He eventually ground out victory after three hours and 18 minutes and moves through to a second-round clash with 31st seed Fernando Verdasco.

The Scot said: "At times it was tricky especially early on, it was very lively, very hot. James was serving big and playing a lot of drop shots, throwing me off rhythm. I was happy I managed to get through that and play some good stuff at times.

"I've lost a lot of matches out here over the years, I've struggled a lot, but it's like a new beginning. It was beautiful, a great atmosphere and I'm very, very happy to be back."

Murray never seemed comfortable in the tight confines of the old Louis Armstrong, so the space and airiness of the new court - as well as some shade - was very welcome.

And he said his fitness was quickly improving having completed just his eighth match this year.

"The discomfort I have been feeling in my hip was a lot better than it was over the grass-court season," he said.

I've got a bunch of matches under my belt, a lot more training and just a better understanding of where my body is at."