QUEBEC -- Canada's Eugenie Bouchard defeated Kazakhstan's Sesil Karatantcheva 7-6 (2), 6-4 on Thursday to advance to the quarter-finals of the Bell Challenge.
The 19-year-old from Montreal, who is seeded No. 5 at the tournament, will face second-seed Kristina Mladenovic of France in the final eight on Friday night.
Bouchard raced out to a 4-0 double break lead in the opening set, but Karatantcheva fought back to force a tiebreak.
Bouchard then went down a break in the second set, but recovered in time to seal the victory.
"I'm happy I was able to stay with her. I fought really well even though I wasn't playing my best," Bouchard said. "I gave it my all and I was able to turn around the match and the second set as well. I started to be more aggressive and that made the difference."
Bouchard is the first Canadian to reach the quarter-finals of the Bell Challenge since Rebecca Marino in 2011.
Mladenovic advanced to the quarters after Crotia's Petra Martic retired while trailing 6-3, 2-3.
In other action, Croatia's Ajla Tomljanovic defeated No. 4 Bethanie Mattek-Sands of the United States, who retired while trailing 7-5, 3-6, 4-1, No. 3 Lucie Safarova of the Czech Republic topped Croatia's Mirjana Lucic-Baroni 7-6 (4), 7-6 (10), and No. 7 Lauren Davis of the U.S. downed Andrea Hlavackova of the Czech Republic 6-1, 2-6, 6-3.
In doubles, Carol Zhao of Richmond Hill, Ont., and Montreal's Francoise Abanda lost 7-6 (4), 7-5 to Russia's Alla Kudryavtseva and Australia's Anastasia Rodionova in the quarters.