Eugenie Bouchard gave Canada a 2-0 lead over Slovakia on Saturday in the Fed Cup World Group playoff tie at Laval University.
It took world No. 18 Bouchard two hours seven minutes to beat No. 137 Kristina Kucova in three sets 7-6 (0), 2-6, 6-1.
The Montreal native started very slowly, not being able to find her rhythm, committing unforced errors and double faulting on important points.
Down 0-3 in the opening set, Bouchard started winning some key rallies, and after tying the set 6-6 she won seven points in a row in the tiebreaker to take the first set 7-6.
But Kucova, who never finished a season being ranked inside the WTA's Top 100, played with even more determination. Hitting winners off both sides with her two-handed groundstrokes she won the second set quickly and decisively.
Bouchard then centred herself and cruised to a 6-1 win in the final set.
Earlier, Aleksandra Wozniak earned a 4-6, 7-5, 7-5 win over Jana Cepelova in the first match of the tie.
The Blainville, Que., native trailed 2-5 in the second set before she began playing more confidently off the ground, moving her opponent around the court and forcing errors from the young Slovak.
Cepelova, ranked almost 100 spots higher than Wozniak, twice served for the match in the second and third sets but couldn't finish off the win.
Canada can secure a spot in the World Group I for 2015 in the first reverse singles match, when Bouchard plays Cepelova.
The Canadians only need to win one match on Sunday to beat Slovakia for a place in the elite World Group.
After the first match between Bouchard and Cepelova, Wozniak will face Kucova, and in doubles competition Toronto's Sharon Fichman and Ottawa's Gabriela Dabrowski will play Janette Husarova and Cepelova.