SHANGHAI (Reuters) - Rafael Nadal failed to reach a final for only the second time during his incredible 2013 season, after being defeated 2-6, 4-6 by Argentina's Juan Martin del Potro at the Shanghai Rolex Masters on Saturday.

The Spaniard had been hoping to celebrate his return to the top of the world rankings this week by setting up a final showdown with rival Novak Djokovic.

But Nadal, one of the fastest athletes on the tour, found himself outpaced after a breathtaking display of power and touch by del Potro, the 2009 US Open champion.

The result condemned French and US Open champion Nadal to his earliest defeat since a shock first-round exit from Wimbledon in June, the only other time this year he failed to reach the final of an event he had featured in.