Women's world number one Aryna Sabalenka suffered a surprise defeat in the Canadian Open weeks before her US Open title defense. She lost 7-6 (7-3) 4-6 6-4 to Russia's Ekaterina Alexandrova in Toronto. Despite recovering from a set down, a double fault handed the number 16 seed victory in a match lasting almost two and a half hours.

In the women's draw, third seed Jessica Pegula suffered her first career loss to Diana Shnaider. Meanwhile, Iga Swiatek secured a spot in the semi-finals after overcoming opening set service troubles to defeat Marta Kostyuk 3-6 6-1 6-2.

In the men's event in Montreal, Britain's Cameron Norrie bowed out in the last 16. He spurned two set-point opportunities and was defeated 6-2 7-6 (10-8) by 18th seed Arthur Fils. Fils will meet Spanish teenager Rafael Jodar in the quarter-finals following Jodar's upset of Jiri Lehecka.