SYDNEY, Jan 8 (Reuters) - Denis Shapovalov and Felix Auger-Aliassime rallied to victory in the deciding doubles rubber against defending champions Russia to fire Canada into their first ATP Cup final on Saturday. The Canadians beat the Russian pair of Daniil Medvedev and Roman Safiullin 4-6 7-5 10-7 in a final set super tiebreaker to seal the tie 2-1 and set up a Sunday final in the $10 million team event against Spain. After Shapovalov and Medvedev won their respective singles matches, all four players were back at the Ken Rosewall Arena for the doubles. The Russians appeared to have the upper hand before Canada levelled the match with a late break of serve in the second set and then carried the momentum in the super tiebreaker, which is played to 10 points instead of seven. "Felix played unbelievable in the game to break and then in the tie-break as well, just making them play so much. It was awesome," Shapovalov said. "We kept fighting. We have great team chemistry, team spirit, so it helped us a lot." Earlier, world number two Medvedev strolled past Auger-Aliassime 6-4 6-0 to keep alive Russia"s hopes of defending their ATP Cup title, sending the semi-final tie into the deciding doubles. Denis Shapovalov had put Canada within one win of reaching the final with a battling 6-4 5-7 6-4 victory over Roman Safiullin in the first singles, putting Medvedev in a must-win situation in the second rubber. Medvedev delivered in style with a flawless performance against 11th-ranked Auger-Aliassime, making it one-way traffic in the match after grabbing the first break in the ninth game of the opening set. Playing from well behind the baseline, the U.S. Open champion forced Auger-Aliassime to go for his shots, contributing to a spiral of unforced errors by the Canadian. A depleted Russia, who beat Italy in last year"s final, came into the tournament without fifth-ranked Andrey Rublev and world number 18 Aslan Karatsev after both tested positive for COVID-19 in the lead-up to the team event. In his first career meeting against the 167th-ranked Safiullin, the left-handed Shapovalov dominated proceedings to take the opening set, but the gritty Russian levelled things after his opponent hit an overhead smash into the net. Safiullin looked set to forge ahead for an upset win against the 14th-ranked Shapovalov when he had six breakpoints at 2-1 in the deciding set. But the 22-year-old saved all of them to hold serve and then used the shift in momentum to break for 4-3. Shapovalov, who had contracted COVID-19 in the lead-up to the ATP Cup, did not look back from there and completed the win in two hours and 39 minutes. "Denis helped me and the team to push myself. We had a tough start in the doubles, so to be able to come back in this way, it"s really a team effort," Auger-Aliassime said. "That"s what the ATP Cup is about. You can still win after being one-all and losing a tough singles. It"s really about the team effort and we"re happy to be through. We"re really thrilled for the whole team."