Rafael Nadal's resurgence continued as he reached the semi-finals of the Shanghai Masters with a three-set victory over Grigor Dimitrov.

The Spanish world No.1 defeated Dimitrov en route to winning the China Open last week and he repeated the success with a 6-4, 6-7 (6/8), 6-3 win yesterday, extending his winning streak to 15 matches.

It looked like Nadal, leading 4-2 in the second set tie-break, would win in straight sets, but the Bulgarian reeled off five straight points to level things up.

Nadal saved a break point at 2-2 in the decider, and is still to lose his serve in Shanghai, before breaking serve in the next game and going on to win to set up a semi-final clash with Marin Cilic.

Fourth seed Cilic has reached the last four without dropping a set and overcame Nadal's countryman Albert Ramos-Vinolas 6-3, 6-4, although the Spaniard did manage to break Cilic's serve for the first time in the competition at 3-3 in the second set.

On the other side of the draw, Juan Martin del Potro overcame a nasty tumble to beat Serbia's Viktor Troicki 4-6, 6-1, 6-4.

Del Potro's wrist problems have been well documented down the years and at 2-2 in the deciding set he fell awkwardly on to his non-playing hand, dropping on to it with most of his weight.

The Argentine needed several minutes of medical attention while he sat on a chair on the back of the court, visibly wincing in pain.

However, on his return to action he immediately broke Troicki's serve and went on to win.

Del Potro will play Roger Federer after he saw off Richard Gasquet 7-5, 6-4.

Jamie Murray and Bruno Soares, meanwhile, have booked their place at the ATP World Tour Finals for the second successive year.

The British-Brazilian pair were all but certain of qualifying for the glitzy event at the O2 Arena next month and crossed the line thanks to their quarter-final victory at the Shanghai Masters yesterday.

Last season Murray and Soares, who won both the Australian Open and US Open titles in 2016, clinched the year-end world No.1 team ranking by virtue of reaching the semi-finals in London.

They have not been as successful at the grand slams in 2017, failing to progress beyond the quarter-finals at any tournament, but have won ATP Tour titles in London, Acapulco and Stuttgart and reached three more finals.

The pair currently sit fourth in the 2017 doubles team rankings, with Murray individually ranked ninth and Soares 10th.

This will be Murray's third consecutive appearance at the event, which begins on November 12, having qualified for the first time with John Peers in 2015.

Murray is almost certain to be the only home representative, with brother Andy likely to sit out the rest of the season with his hip injury.