Jessica Pegula ended the hopes of home hope Aleksandra Wozniak in the first round of the Coupe Banque Nationale in Quebec.
Wildcard Wozniak lost the first set 6-3 but squared the match when she won the second set by the same margin.
However, the 29-year-old from Montreal was broken in the second game of the deciding set and her challenge ended there, with America's Pegula wrapping up the set 6-2.
That match took an hour and 54 minutes to complete - but eighth seeded American Samantha Crawford needed more than two hours to see off Belgium's Ysaline Bonaventure, 7-6 6-7 6-4.
The night's final action saw American qualifier Danielle Lao spring a surprise by knocking out third seed Mirjana Lucic-Baroni 6-4 6-2.
Another American qualifier, Lauren Davis, also went through in straight sets, ousting another Canadian - wildcard Carol Zhao 6-3 6-2.
Elsewhere there were straight-set wins for Russian pair Alla Kudryavtseva and Evgeniya Rodina and American duo Julia Boserup and Catherine Bellis.
Source: PA
