British number two Dan Evans pushed Spanish great Rafael Nadal in their first meeting before losing in straight sets at the Rogers Cup.
Evans, 29, was beaten 7-6 (8-6) 6-4 in a second-round match disrupted by rain in Montreal, Canada.
British number one Kyle Edmund is also out after a 59-minute, 6-3 6-0 defeat by Russian eighth seed Daniil Medvedev.
The heavy loss for Edmund came just a day after he beat Australian Nick Kyrgios in straight sets.
In the doubles, Edmund and American Taylor Fritz – who won the singles title at Eastbourne – are through to the second round after beating Nikoloz Basilashvili and Jan-Lennard Struff 6-3 6-4.
But Andy Murray and Spanish partner Feliciano Lopez exited in the second round, beaten 2-6 6-3 10-8 by French duo Jeremy Chardy and Fabrice Martin.
Elsewhere in the singles, Austria’s Dominic Thiem beat Canada’s Denis Shapovalov 6-4 3-6 6-3 and will face Croatia’s Marin Cilic after the 14th seed defeated Australia’s John Millman 6-3 6-4.
Frenchman Richard Gasquet upset Japanese fifth seed Kei Nishikori 6-7 (6-8) 6-2 7-6 (7-4) while Wimbledon semi-finalist Roberto Bautista Agut of Spain beat Argentina’s Diego Schwartzman 6-2 7-5.