Reigning Coupe Banque Nationale champion Mirjana Lucic-Baroni survived a tough quarter-final in Quebec City, while Naomi Broady's fairytale run continued.
Lucic-Baroni lost the opening set of her quarter-final to world 217 Samantha Crawford but recovered to triumph 4-6 6-4 6-1 and set-up a semi-final clash with fifth seed Annika Beck.
American qualifier Crawford broke Lucic-Baroni in the 10th game of the opening set to take a step towards the semi-finals and gave the Croatian second seed a further scare when she surged to a 2-0 lead in the second on Friday.
But Lucic-Baroni won 10 of the next 12 games to claim the second set and power to a 4-0 lead in the third before eventually clinching victory in one hour, 41 minutes.
Beck will be Lucic-Baroni's next opponent as the 33-year-old looks to defend her title, after the German 21-year-old defeated Czech fourth seed Lucie Hradecka 6-0 6-3.
Broady - a lucky loser - overcame Anna Tatishvili 3-6 7-5 6-3 in Canada to notch her third win at the WTA International event as she aims for her maiden WTA final.
The 25-year-old Brit will face Latvia's Jelena Ostapenko in the semi-finals after the latter thrashed Paula Kania 6-0 6-1.