NEW YORK - Roger Federer’s hopes of claiming a record-extending 20th grand slam title ended on Wednesday when he was beaten 7-5 3-6 7-6(8) 6-4 by Juan Martin del Potro in a thrilling U.S. Open quarter-final.

Del Potro, who swept aside Federer in the 2009 final at Flushing Meadows, now faces world number one Rafa Nadal, denying fans a potential first encounter between the Swiss maestro and Spaniard in New York.

Federer had predicted that he would need to overcome Del Potro’s serve, forehand and fighting spirit to advance to the semi-finals. On Wednesday, he was dead right.

Del Potro hit huge forehands, big serves and stayed focused when Federer seemed to be back in control in a one-sided second set.

"I think I played my best match of the tournament, I did everything well,” said the 24th seeded Argentine. "I served so good, I hit my forehand as hard as I could and I think we played a great match and I think I deserved to win.”

Del Potro enjoyed strong support from the sold-out 23,771 crowd on Arthur Ashe under the lights, with a spine-chilling roar welcoming his victory.

"I think it’s my homecourt, too, you make me feel happy everytime I play here and I love your support guys. I love to see you cheer for me,” he told the crowd.

Federer had tried to stay away from Del Potro’s lethal forehand throughout the match, but with the Argentine’s first-serve percentage at 79 in the first set, he had no chance to break.

With the Swiss struggling with his own serve, the lanky Argentine had one opportunity at 5-5 when the Swiss hit a double fault and then punished him with a splendid forehand passing shot.

Agencies