Argentina's Juan Martin del Potro, the runner-up in Montreal in 2009, downed Finland's Jarrko Nieminen 6-4, 6-0.
The top eight seeded players drew first-round byes.
In other matches, Kevin Anderson of South Africa beat Spain's Pablo Andujar 6-4, 6-4; Ernests Gulbis of Latvia defeated Juan Carlos Ferrero of Spain 3-6, 6-1, 7-5; and Brazil's Thomaz Bellucci also advanced with a 7-5, 7-6 (5) win over Andrey Golubev of Kazakhstan.
No. 21-ranked Alexandr Dolgopolov topped Erik Chvojka 6-3, 5-7, 6-4 and Thomaz Bellucci of Brazil knocked out Andrey Golubev of Kazakhstan, 7-5, 7-6 (6).
Ivo Karlovic of Croatia edged Juan Monaco of Argentina 6-7 (2), 6-3, 7-6 (5); Russia's Alex Bogomolov beat France's Adrian Mannarino, 6-2, 7-6 (4); Croatia's Ivan Dodig beat Jeremy Chardy of France, 6-3, 6-4; and Marin Cilic of Croatia defeated Italy's Andreas Seppi 7-5, 6-4. Russia's Nikolay Davydenko beat Italy's Flavio Cipolla 6-3, 6-3; Australian wild card Bernard Tomic beat Taiwan's Lu Yen-Hsun 7-6 (5), 6-3.
In an evening ceremony, Jimmy Connors was officially inducted into the Rogers Cup Hall of Fame.