Canada set their sights on a first Davis Cup final on Saturday after opening a 2-1 semi-final lead over hosts Serbia when Daniel Nestor and Vasek Pospisil defeated Nenad Zimonjic and Ilija Bozoljac in the doubles.

In the four-hour rubber, Serbia led twice, but Canada levelled and won 6-7 (6/8), 6-4, 3-6, 7-6 (5/7), 10-8.

The doubles match opposed former partners Zimonjic and Nestor who won Wimbledon twice (2008 and 2009) and the 2010 French Open.

Zimonjic and Bozoljac, stars of Serbia's quarter-final win against the United States when they stunned Bob and Mike Bryan by winning the fifth set of their encounter 15-13, failed to repeat the success against the Canadians.

After Serbia had taken the first set on a tiebreak, Nestor's brilliant performance and Zimonjic's poor serving allowed the Canadian pair to level.

Boosted by some 8,000 funs at Belgrade Arena, Serbia capitalised on a break of Nestor's serve and kept the advantage for the third set.

After Canada levelled the rubber on a fourth-set tiebreak, the epic final set turned on a break of the Zimonjic serve in the 17th game.

"Today was one of those matches where it was hard to have a loser. We need one more match, hopefully we can get it," said Nestor.

The finalists will be known Sunday, when world number one Novak Djokovic faces Montenegro-born Milos Raonic, the world number 11, before 23rd-ranked Janko Tipsarevic plays against Vasek Pospisil, the world number 41.

Serbia were in a similar position in their 2010 semi-final against the Czech Republic, but managed to win both singles on the final day.

They eventually went on to win a maiden title.

"The guys did their best. We have to win the match in singles on the third day," Serbian coach Bogdan Obradovic said.

Canada's coach Martin Laurendeau couldn't hide his satisfaction.

"This is Davis Cup, this is why the guys play the game -- it's a moment we've been waiting for a long time. The weekend isn't over yet, we're facing the world No.1 tomorrow and this is a very tough crowd," he said.

The winners will advance to November's final against defending champions Czech Republic who earlier Sunday defeated Argentina 3-0.