Magnificent Murray sets up semi final clash with Nadal -| slideshow

ANDY Murray scaled new heights last night when he reached the first grand slam semi-final of his career.

• Watch a picture slideshow of the match here

In a thrilling match lasting three hours and 58 minutes, the Scot produced a courageous performance to defeat Juan Martin Del Potro of Argentina 7-6 (7-2), 7-6 (7-1), 4-6 7-5 and set up a last four match against number one seed Rafael Nadal.

The victory at Flushing Meadow in New York means he is now guaranteed to rise to fourth in the world, regardless of his result in the semi-final.

"Overall I'm very relieved," said Murray, who becomes the fifth British player to reach a grand slam semi-final in the open era. "I had my chances in the third set and let it slip. But Juan has been on a great run so he had some confidence and fought hard. It was a great atmosphere at the end of the match."

Del Potro, 19, matched Murray's power from the baseline in the opening two sets but each time faded in the tiebreak.

After venting his frustrations by repeatedly slamming his racket to the ground, Del Potro came alive when the Scot came within two games of victory. Ripping a series of stinging passing shots, he broke Murray for 5-4 and wrapped up the third set with a crisp forehand winner.

Both players appeared reluctant to snatch control of the match in the fourth until Murray pounced on a forehand error by Del Potro to earn two match points.

The first went begging but the Scot let out an almighty roar when a Del Potro's backhand floated wide on the second.

Nadal booked his semi-final berth by defeating Mardy Fish 3-6 6-1 6-4 6-2.

Nadal has without question been the best player in tennis this year and last month overtook Roger Federer at the top of the world rankings, ending the Swiss star's four-and-a-half-year reign at number one.

The five-time grand slam champion earned that honour just a day after claiming his first gold medal at the Olympics, which marked his ATP-leading eighth title of the year.

Nadal went into this quarter-final clash against Fish having never lost to the American but suffered a setback when he lost the first set 6-3.

That proved to be the only blip for the 22-year-old, however, as he took the next two sets and in the seventh game of the fourth set broke Fish's serve to go 5-2 ahead.

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Watch an interview with Andy Murray here