Simona Halep and Johanna Konta made it through at the Rogers Cup as all the seeds won on Tuesday.
Halep, last year's runner-up in Montreal, eased past Daria Gavrilova in straight sets while Konta, winner of the Bank of the West Classic last week, beat Shelby Rogers in the same fashion.
Dominika Cibulkova defeated Mariana Duque-Marino, while Madison Keys was too strong for Elena Vesnina.
Karolina Pliskova also won against Kateryna Bondarenko as all seeds were victorious at the WTA Premier event.
HALEP, KONTA PROGRESS
The fifth-seeded Halep cruised past Australian Gavrilova 6-2 6-3 in the second round.
Meanwhile, in the first round, Konta broke Rogers five times as she advanced in one hour, 21 minutes, winning 6-4 6-2.
GREAT DAY FOR SEEDS
Every seed in action progressed on Tuesday, with none knocked out after two days of action.
Pliskova needed a third set, seeing off qualifier Bondarenko 3-6 6-2 7-5.
Garbine Muguruza withdrew due to illness and her replacement, Varvara Lepchenko, got past Naomi Broady 6-4 3-6 6-3.
WICKMAYER AND BABOS DEFEATED, BOUCHARD BATTLES THROUGH
Belgian Yanina Wickmayer suffered a shock loss to world number 121 Kristina Kucova, as the Slovakian qualifier came from behind to record a 4-6 6-2 6-3 win.
Timea Babos battled but went down to Vania King 6-4 3-6 7-6 (7-5) in over two and a half hours, while Eugenie Bouchard defeated Lucie Safarova 6-3 3-6 7-6 (7-3).
KERBER, VENUS BEGIN CAMPAIGNS
Angelique Kerber begins her campaign against Mirjana Lucic-Baroni, while the sixth-seeded Venus Williams comes up against Barbora Strycova.