Milos Raonic of Thornhill, Ont., and Vasek Pospisil of Vernon, B.C., won their doubles match Saturday to give Canada a 2-1 lead over Mexico in its Davis Cup tie.
Raonic and Pospisil took a 4-6, 6-3, 6-4, 6-4 decision over Mexicans Luis Diaz-Barriga and Miguel-Angel Reyes-Varela in doubles. Canada can cement the best-of-five Americas Zone Group I first-round tie by winning one of the two singles matches Sunday.
Pospisil was playing doubles in place of Toronto's Daniel Nestor, who is nursing an inflamed Achilles tendon.
"It felt really good getting my first meaningful Davis Cup win," said Pospisil. "I had really big shoes to fill replacing Daniel Nestor on the team.
"But Milos and I have good chemistry on the court and off the court and I think our experience together as well as our big serving really worked for us."
Davis Cup roundup
Sweden, Spain and Argentina rolled into the Davis Cup quarter-finals on Saturday with a day to spare.
Sweden accounted for Russia in Boras, Spain didn't drop a set against Belgium, and Argentina nailed down Romania.
In the other first-round ties, defending champion Serbia led India 2-1, the United States was ahead of Chile, Germany led Croatia, France has the advantage over Austria, and the Czech Republic led Kazakhstan.
Raonic, who is ranked No. 37 in the world, plays Mexico's Daniel Garza in one singles match while Frank Dancevic of Niagara Falls, Ont., takes on Manuel Sanchez in the other.
The games are being played on clay.
A win over Mexico will send the Canadians to a second-round pairing with Ecuador in July. A loss would force them to play a relegation tie to keep their spot in Americas Zone Group I for 2012.
Raonic defeated Sanchez 6-2, 6-2, 6-1 on Friday to pull Canada into a 1-1 tie with Mexico after Garza, ranked No. 439, rallied to defeat Dancevic, ranked No. 202 in the world, 2-6, 4-6, 6-2, 6-3, 6-4 in the series opener.