Shanghai - World number one Rafael Nadal was on Thursday dumped out of the $3.24m Shanghai Masters in the third round by Austrian 13th seed Jurgen Melzer.
It was only the ninth defeat of the season for the Spaniard, who came into this tournament on the heels of victory in the Japan Open last week.
It was also the first time since the 2009 French Open that he has failed to progress further than the third round: in the 21 tournaments since then, Nadal has reached at least the quarter-final stage.
Despite never having taken a set off Nadal in their three previous encounters, Melzer stormed the first set here, winning 6-1.
Nadal claimed the second, 6-3, but the Austrian ranked 12th in the world rankings, took the third, decisive set 6-3 to set up a quarter-final against either Juan Monaco or Mischa Zverev.
Three straight weeks of play in Asia capped an exhausting year for Nadal, winner of seven titles including Tokyo last weekend and the last three grand slams.
Nadal takes a pause standing 67-9 on the season and will headline at the eight-man season finals in London from November 21.
Melzer handed Nadal his first 6-1 losing set in a year. The top seed bounced back to take the second but the Austrian recovered in the third, earning a break for 4-2.
He kept Nadal under pressure a game later, as the world number one saved three match points to hold on for 3-5. But Melzer held his nerve to serve out victory a game later.
Roger Federer, seeded third, was completing third round play against Andreas Seppi, who has never beaten him.
Andy Murray became the fourth man to qualify for the season's final event as he defeated Jeremy Chardy 6-3 6-4 to reach the quarter-finals.
Fellow London qualifier and world number two Novak Djokovic continued his red-hot form, with the two-time Beijing champion hammering Richard Gasquet 6-1, 6-1.
"I'm feeling good on the court," said Djokovic, winner in Beijing before coming to Shanghai.
"I'm hitting the ball and playing better and better every day. So I'm just hoping that it's going to stay that way in the upcoming rounds."
Murray, Djokovic, Nadal and Federer will now be among the eight players in the London finals.
"It's a great achievement," the Scot said of his success.
"I'm obviously very happy to have done it with a few tournaments left. Today was a good match. I'm happy with how I played."
Murray saved the five break points he faced from the Frenchman, whom he has now defeated in all three of their meetings.
Robin Soderling, Wimbledon finalist Tomas Berdych, David Ferrer and injured Andy Roddick are the next four in the queue for London qualification.
But results over this week and the next four through to the end of the regular ATP season will decide the final line-up for the World Tour Finals.
Elsewhere in the third round on another rainy day, Swedish fifth seed Soderling beat Spaniard David Ferrer 7-5, 6-4 while number 15 Jo-Wilfried Tsonga stopped Florian Mayer 7-5, 6-3 to lineup against Murray.
Spain's Guillermo Garcia-Lopez, who beat Nadal in the Bangkok semis a fortnight ago, put out Czech seventh seed Tomas Berdych 7-6 (7/4), 6-3.