The Britsh sixth seed Andy Murray roared in relief as he celebrated reaching his first grand slam semi-final after ending the US Open campaign of Argentine teenager Juan Martin Del Potro 7-6 7-6 4-6 7-5 in New York.
The 21-year-old Murray, who was dominant in the tiebreakers, winning the first 7-2 and the second by 7-1, overcame shaky moments in an error-filled third set before ending the four-hour match as Del Potro served to stay alive.
Murray says he had his chances in the third set but let it slip before recovering to snap Del Potro's 23-match winning streak to set a match with Rafael Nadal or the unseeded American Mardy Fish.
The Russian sixth seed Dinara Safina also registered a personal first at Flushing Meadows when she overpowered Italian Flavia Pennetta 6-2 6-3 to reach the semi-finals for the first time.
