World number one Rafael Nadal was dumped out of the Shanghai Masters Saturday by an inspired Juan Martin del Potro, who blew the Spaniard away in a brutal display to set up a final against Novak Djokovic.
The giant Argentine, fresh from winning the Japan Open, went into the semi-final at the Qizhong Tennis Center trailing 8-3 in head-to-heads, but rocked Nadal with a double break in the first set and kept up the pressure to win 6-2, 6-4.
Earlier, top seed Djokovic swept aside Jo-Wilfried Tsonga 6-2, 7-5 to earn the chance to defend his title.
Nadal has enjoyed one of the best seasons of his career, winning 10 titles including the French Open and the US Open, and came into the match with the smart money on yet another final showdown on Sunday with Djokovic.
But the 13-time Grand Slam champion was given the run-around by the former US Open champion, 25, who launched a sustained and blistering all-court attack from the start, achieving the rare feat of out-hitting his illustrious opponent to gasps from the excitable crowd.
"I played so solid all the time, hitting the ball so hard," said Del Potro. "I saw Rafa playing very far off the baseline, which is good for my game, for my serve, and confidence. That's the way to beat this guy."
And he said he could play even better after serving just five aces against Nadal.
"I didn't make too many aces for playing against the number in the world," he added. "That's what I need tomorrow against Djokovic. I need to win easy points with my serves. Hopefully, my forehands and backhands work like today in the final. I'll be aggressive like today."
Dominating from the baseline on both forehand and backhand sides with shots of withering power, the sixth seed raced into a 4-0 lead in the first set as Nadal desperately searched for a foothold.
A single break was enough in the second set for the six foot six inch (1.98 metre) Argentine, who hit a total of 28 winners and 31 unforced errors, landing 80 percent of first serves in his victory, which also secures him a place at next month's World Tour Finals in London.
A rueful Nadal, who uncharacteristically failed with all six of his break point opportunities, admitted that he was beaten by the better player.
"Very few times I have played against a player with a level like today I played against... At the end I played against a player who served 80 percent of first serves, who hit every ball as hard as he can I think, and with no mistakes," said the 27-year-old.
In the first semi-final, Tsonga landed just 46 percent of first serves in a one-sided first set, and despite an improved showing in the second, he cracked in the 12th game as Djokovic completed a straight-sets win.
"I think I raised my game today compared to last night's match," said Djokovic, 26, who lost his cool midway through the second set over a couple of line calls before re-finding his focus.
"Of course, I would wish to get even a better performance tomorrow for the most important match this week. But we'll see."
A more balanced second set involving a break apiece looked to be heading towards a tie-break, but the Serb made the decisive move, breaking again to claim victory on his second match point.
Djokovic has a 9-3 winning record against Del Potro. Their most recent match was a gruelling five-setter at this year's Wimbledon semi-final, won by the Serb.
Nadal and Djokovic are among the three other players who have already secured their places at next month's elite World Tour Finals, featuring the season's top eight players.