Rafael Nadal quits US Open semi-final sending Juan Martin del Potro through

Rafael Nadal angry

Juan Martin del Potro is through to the US Open final after Rafael Nadal retired hurt in their semi-final.

The world number one was struggling throughout, and opted to withdraw with a knee injury after Del Potro took a two set lad.

The first set was a very tight affair with Nadal probing the Del Potro backhand, and the pair traded breaks before the Argentinian finally sealed it with a tiebreak.

However, Nadal’s lack of mobility started to really show in the second set.

The defending champion has battled through some long matches in the tournament so far, with a near five-hour epic against Dominic Thiem in the quarter-finals possibly the final straw for his knee.

And, after dropping the second set 6-2, Nadal withdrew allowing Del Potro to take his place in the final of the tournament he won in 2009.

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