Alla Kudryavtseva surprised top seed Eugenie Bouchard in the second round of the Coupe Banque Nationale in Quebec on Thursday.
Russia's Kudryavtseva beat the home hope 6-2 6-3 in 82 minutes to book a quarter-final meeting with American qualifier Lauren Davis.
Another American, Jessica Pegula, will play Tereza Martincova for a place in the semi-finals after seeing off Canada's Francoise Abanda 7-6 7-5.
Earlier, France's Oceane Dodin defeated America's Sachia Vickery 6-4 6-4 to set up a quarter-final against Belgium's Alison Van Uytvanck, a 6-4 6-3 conqueror of the Czech Republic's Barbora Stefkova.
Source: PA
