(CNN)) -- Nikolay Davydenko avenged last year's Tennis Masters Cup final defeat by Novak Djokovic to upset the world No. 3 in the semifinals of the Shanghai Masters on Saturday.
Nikolay Davydenko will be seeking to upset Rafael Nadal and claim his fourth title of 2009.
The Russian sixth seed triumphed 4-6 6-4 7-6 (7-1) in a three-hour epic to earn a showdown with world No. 2 Rafael Nadal, who had an easier passage into the final when Feliciano Lopez became the tournament's ninth injury victim.
Davydenko, beaten by Djokovic when the Chinese city held the season-ending finale last season, boosted his chances of qualifying for its 2009 incarnation as he moved into seventh in the standings above Spain's Fernando Verdasco.
Eight players will take part in the ATP Tour World Finals in London late next month, with world No. 1 Roger Federer, Nadal, Djokovic, Andy Murray and Juan Martin Del Potro already assured places.
Djokovic saved three break-points in the first set, which he won in 57 minutes when he broke Davydenko's serve in the 10th game.
But the Serb lost his own serve in the seventh game of the second set and and then again in the ninth to send the match to a decider, which went with serve to require the tie-breaker.
Davydenko romped to a 5-0 lead as he advanced to his 23rd final on the ATP Tour, where he will seek his fourth title of this year.
"The match was three hours [in duration] and decided on a tie-break," he told the ATP Tour's official Web site. "Who was better? I don't know. He was better, but I won. He made many mistakes and also lost concentration."
Top seed Nadal will be seeking his sixth title this season -- but his first since May -- having led 6-1 3-0 against Lopez when his fellow Spaniard was forced to retire with an ankle injury.
Nadal, who lost his No. 1 ranking following knee injuries which meant he was unable to defend his Wimbledon title, is seeking to join Federer in second place in all-time Masters event victories with his 16th such title.
He has a 4-2 winning record against Davydenko, who he defeated in the semifinals in Barcelona in their last encounter in April.