The British number one and sixth seed, who faces in-form number 17 seed Juan Martin Del Potro of Argentina in the quarter-finals, feels better equipped to reach his first grand slam semi-final than earlier this summer at Wimbledon when he was blown away by Spain's Rafael Nadal in the quarters.

"The last slam quarter I played I got killed and Nadal played way too good for me but I feel like I'm playing better now." said the Scotsman.

He added: "I'm definitely going to be more rested this time round and I'll hopefully play a better match."

Murray, 21, will also have the benefit of feeling totally at home at the Billie Jean King National Tennis Centre in New York, where he won the Junior Boys' singles' title in 2004 and at what he has repeatedly said was his favourite tournament.

"Regardless of how I am playing before I come to the States, I feel good every time I come on those courts," he added.

"I played great when I was a junior here and I've had some good results here in the past. I just really enjoy playing here.

"So even if I haven't brought it into the tournament, feeling great beforehand, just as soon as the tournament starts I've always felt comfortable here."