Wounded Del Potro into Shanghai semis

Shanghai - Juan Martin Del Potro clambered off the court floor to knock out Serbia's Viktor Troicki 4-6, 6-1, 6-4 and bravely seal a spot in the semi-finals of the Shanghai Masters on Friday.

The Argentine 16th seed faces Swiss great Roger Federer or unseeded Frenchman Richard Gasquet on Saturday for a place in the final.

Del Potro, who has suffered years of wrist injuries that have threatened his career, took a nasty tumble at 2-2 in the deciding set.

His foot appeared to get stuck on the floor and he crumpled down, landing with his weight on his outstretched left hand - his non-playing hand - and bending it painfully backwards.

He needed several minutes of medical attention and sat on a chair on the back of the court, wincing in obvious distress.

Incredibly, he broke the serve of the unseeded Troicki on his immediate return to action.

Results from the ATP Shanghai Masters on Friday (x denotes seeding):

Juan Martin del Potro (ARG x16) bt Viktor Troicki (SRB) 4-6, 6-1, 6-4

Rafael Nadal (ESP x1) bt Grigor Dimitrov (BUL x6) 6-4, 6-7 (4/7), 6-3

Marin Cilic (CRO x4) bt Albert Ramos-Vinolas (ESP) 6-3, 6-4