Del Potro knocks out Federer; sets up Nadal clash in semis

New York, September 7: A massive forehand down the line winner pushed Juan Martin del Potro into the semifinals of the US Open on Thursday (September 7).

The Argentine knocked out Roger Federer, whom he had beaten for his US Open title in 2009, 7-5, 3-6, 7-6, 6-4 in the quarterfinals.

Now, del Potro, who had to battle illness and patchy form ahead of the season's final Grand Slam, will face world number one Rafael Nadal in the semis.

(More to follow)