Serena Williams recovered from a shaky start to see off France's Stephanie Cohen-Aloro in the second round of the Rogers Cup in Toronto.
In her first tournament since Wimbledon, Williams struggled with her mobility in a 3-6 6-4 6-2 win.
Cohen-Aloro broke Williams three times to win the first set before the fifth seed American raised her game.
Defending champion Amelie Mauresmo cruised past Madagascar's Dally Randriantefy 6-2 6-3.
With the US Open just over two weeks away, Williams is keen to use the Toronto event as a desperately needed tune-up for the final Grand Slam of the season.
Williams gained confidence after going a break up in the second set, making fewer unforced errors and putting more pace on her serve.
After breaking Cohen-Aloro's serve in the opening game of the third set, Williams raced into a 3-0 lead and effectively put the match out of her opponent's reach.
World number three Mauresmo cruised into the third round in her first Tour match since Wimbledon.
Third seed Svetlana Kuznetsova beat Anabel Medina Garrigues 2-6 7-5 6-4.
Fellow Frenchwoman Mary Pierce withdrew because of the strained right thigh muscle that forced her out of the JP Morgan Chase Open last week.
In other matches, China's Li Na upset 11th seed Jelena Jankovic 6-4 5-7 6-2, and 10th seed Nathalie Dechy beat Fabiola Zuluaga 6-2 6-4.
Twelfth seed Ana Ivanovic defeated Tathiana Garbin 6-2 7-6 (7-3).