Argentina's Juan Martin del Potro ended Rafael Nadal's hopes of a second Olympic singles title Saturday with an epic 5-7, 6-4, 7-6, (7/5) win to set up a gold medal showdown with defending champion Andy Murray.
The world number 141 Del Potro, whose career was almost ended by a series of wrist operations, triumphed after three hours and eight minutes of compelling centre court action.
Second seed Murray reached his second successive Olympic final with a ruthless 6-1, 6-4 demolition of Japan's Kei Nishikori.
Nadal, the 2008 singles champion, had won the men's doubles on Friday with Marc Lopez but playing his 10th match of the Rio tournament finally caught up with him.
Murray can become the first player to defend an Olympic singles gold but he must get past a rejuvenated 2009 US Open champion Del Potro, who shocked world number one Novak Djokovic in the first round.
"It means a lot to me. It's very big, maybe even more special than when I won the US Open," said 27-year-old del Potro who was mobbed by Argentine fans at the end of the semi-final.
"I didn't expect to get to the final; I didn't expect to beat Djokovic. It's just amazing for me."
