Andy Murray believes improving his service return will help him finally beat nemesis Rafael Nadal and reach his first grand slam final.
The sixth seed will attempt to topple the world number one for the first time on Saturday when the duo meet in the US Open semi-finals.
Murray, 21, last night became the first Briton to reach the last four of a grand slam since Tim Henman did the same in New York four years ago.
But if he is to equal the feat of Greg Rusedski, who was runner-up at Flushing Meadows in 1997, he must overcome the man who has won all their previous five meetings and who thrashed him at Wimbledon just two months ago.
"The one thing that I need to improve is to return better," said the British number one, whose most recent defeat to Nadal came in the Toronto Masters semi-finals in July.
"The first couple of times I played him, I returned very well. The last two or three matches, I didn't return well at all. That's the only thing that I need to do better."
Murray, who is set to move two places up the world rankings to number four, is hoping the very quick hard court at Arthur Ashe Stadium will work to his advantage.
"The times I played him on hard courts, I've had quite a few close sets, really tough matches," the Scot said.
"It comes down to who returns better and who gets the breaks of serve.
"Normally, that's the best part of my game. The last few times I've played him, I've not done that."
Following his four-hour quarter-final victory over Juan Martin del Potro, when the 19-year-old Argentinian battled back from two sets and a break down to force a third set, Murray insisted the third long match of his US Open campaign had not affected his fitness.
"I've got two days, so I'll be disappointed if I've not recovered," he said.
Nadal had some exertions of his own in reaching the last four.
The Wimbledon and French Open champion had to come from a set down to defeat American Mardy Fish in a game that finished at 2.10am local time.
The Spaniard, bidding to win his third grand slam this year to emphasise his new-found pre-eminence, is expecting a difficult encounter against Murray.
"He's playing very well and having a very good summer, playing quarter-finals in Wimbledon after playing semi-finals in Toronto, and champion in Cincinnati," said Nadal.
"So he's very, very good player for sure. He's top four, no? So right now, it's going to be a very tough match.
"I have all the respect for him always. In Wimbledon, the same respect like right now. I know how good Andy is and how good he can play.
"So I know the only way to win is to play my best tennis.
"I did very well at Wimbledon and I played one of my best matches there. I beat him in the semi-finals of Toronto, too, but it was a very close match and I played well.
"My goal is try to find my best feeling and my best performance, to give me every chance of winning."