Williams, coming off a victory 2½ weeks ago in the Swedish Open, set up a third-round match Thursday against 13th-seeded Kirsten Flipkens of Belgium. Flipkens edged Kiki Bertens of the Netherlands 7-5, 3-6, 6-2.
"I felt good. I felt solid," Williams said. "I obviously made a few errors but it's just my first match on hard (court) in a really long time. I also played a really good player, so it was a good match."
"I didn't want to put too much pressure on myself because the last two times I played in Toronto I lost first round," said Bartoli, seeded seventh. "So I just wanted to enjoy myself on the court and try my hardest. Obviously being able to win 6-love, 6-3 was pretty good for me."
Also, fourth-seeded Li Na of China topped Russia's Anastasia Pavlyuchenkova 6-1, 6-4; fifth-seeded Sara Errani of Italy edged Klara Zakopalova of the Czech Republic 6-2, 7-6 (2); and France's Alize Cornet of France beat 11th-seeded Maria Kirilenko of Russia 7-5, 7-5.
In late matches, sixth-seeded Petra Kvitova of the Czech Republic edged Canada's Eugenie Bouchard 6-3, 6-2; Romania's Sorana Cirstea knocked off ninth-seeded Caroline Wozniacki of Denmark 5-7, 7-6 (0), 6-4; and and 12th-seeded Samantha Stosur of Australia beat Spain's Carla Suarez Navarro 1-6, 6-2, 6-3.