Novak Djokovic will face Mardy Fish in the final of the ATP Rogers Cup in Montreal, after the Frenchman Jo-Wilfried Tsonga retired in his match against the world No1.

Tsonga had been expected to test Djokovic, after a fine run through to the semi-finals that included a win over Roger Federer, but he pulled out when trailing 6-4, 3-0. A right-arm injury was cited as the problem affecting Tsonga, who had dropped serve in the the second game of the second set.

Djokovic has won 52 of his 53 matches in 2011 and is chasing a ninth title of the year. The 24-year-old Serbian has won on all six of his previous meetings with Fish.

However Fish, the sixth seed, is having the best year of his career, reaching No8 in the world rankings. The 29-year-old is the leading United States player, comfortably ahead of Andy Roddick. He beat another Serbian, the unseeded Janko Tipsarevic, 6-3 6-4 to reach his third final in a month.

Fish won the Atlanta Tennis Championships title and was runner-up at the Farmers Classic in Los Angeles in July.