The fifth-seeded native of Thornhill, Ont., advanced with a 6-3, 6-4 win over Argentina's Juan Monaco. Raonic registered nine aces and twice broke Monaco.
Raonic is looking to reach the quarter-finals or better of an ATP Masters 1000 event for the 10th time in his last 13 events.
Elsewhere, Maria Sharapova advanced to the third round of the women's event by downing Mariana Duque-Marino of Colombia 6-1, 6-2.
The third-seeded Russian broke Duque-Marino's serve four times while saving three break points on her own serve.
Fourth-seeded Petra Kvitova of the Czech Republic also advanced, beating American Coco Vandeweghe 6-4, 2-6, 6-3.
Also, Barbora Strycova of the Czech Republic beat Varvara Lepchenko of the U.S. 6-4, 6-2, and Victoria Azarenka of Belarus defeated Ajla Tomljanocic of Croatia 6-3, 6-3.