The hard-serving native of Thornhill, Ont., will face Colombian Santiago Giraldo in the first of two singles matches Sunday to conclude the best-of-five Davis Cup tie. Canada needs just one victory to secure the victory and assure it remains in the World Group next season.
If Colombia wins both matches, Canada will be knocked out of the World Group.
Canada had a chance to cement the World Group berth Saturday but Colombia's Juan Sebastian Cabal and Robert Farah beat Vancouver's Vasek Pospisil and Toronto's Daniel Nestor 7-6 (4), 7-6 (7), 6-4 in doubles at the Halifax Metro Centre. That cut the Canadians' lead to 2-1 in the tie.
"We knew this was going to be a difficult but we have a lot going for us," Canadian team coach Martin Laurendeau said. "We are up 2-1 . . . and playing in front of a home crowd.
"Those are the conditions we like. We need to regroup now and get the job done (Sunday)."
If Giraldo beats Raonic, the tie will come down to the final singles match between Pospisil and Alejandro Gonzales.
Pospisil and Raonic began play Friday by winning their singles matches. Pospisil beat Giraldo 6-3, 7-6 (2) 6-3 while Raonic dispatched Gonzalez 6-3, 6-3 6-2.
Pospisil said Cabal and Farah were full warranted for their victory.
"It was a very tough match," he said. "They played exceptionally well.
"It was a close match and there were few points here and there that made the difference."
Nestor, participating in his 47th career Davis Cup match, said he knew coming into the match that the Colombians would be tough.
"I played them several times this year (at Brisbane, Barcelona and Madrid on ATP Tour) and all those matches were very close ones," he said. "I was hoping for a different outcome but they were a better team."
Cabal and Farah won first two sets in close tiebreakers. They broke Nestor at 4-4 in the third, then held to complete the sweep.
"We improved a lot this year," said Cabal. "The fact that we can beat Nestor at home shows that we are on the right track to be a very good doubles team."
The contest was a close one. The Colombians won a total of 109 points, just seven more than the Canadians.
"I think we returned the serve better today," said Farah. "That made the difference."
Nestor and Pospisil hadn't played together for over a year and Pospisil felt that was a factor.
"I think this was a big difference," he said. "It's not easy to get ready for both singles and doubles.
"It's tough to get a god rhythm."
Colombian coach Mauricio Hadad admits his team faces a difficult task Sunday needing to win both matches to secure the victory.
"We gave ourselves hope (Saturday) and we're still alive," he said. "But Giraldo has a very difficult match ahead of him.
"Raonic plays very well. He is one of the best players in the world now, and on this fast surface here he is a favourite."
A series win over Colombia would secure Canada's place in the 16-team World Group for a fourth straight year but a loss would drop the squad to the Americas Zone Group I, where it hasn't been since 2011. Colombia is participating in just its third World Group playoff ever and looking to reach Davis Cup's upper echelon for the first time in its history.