On a night when rain delayed the start of play for more than eight hours, world No 4 Raonic fired 12 aces on his way to victory after 94 minutes in the early minutes of Thursday morning.
Raonic, who reached the tie-breaker with his 11th ace and reached match point with his last ace, booked a Friday quarterfinal matchup against British eighth seed Kyle Edmund, who outlasted Taiwan's Lu Yen-Hsun 6-3, 3-6, 6-2.
Also advancing to the last eight was US third seed Jack Sock, who downed Spain's Guillermo Garcia-Lopez 6-4, 6-1, and American fifth seed Steve Johnson, who eliminated Japan's Yoshihito Nishioka by the same score.
Sock and Johnson will meet in another quarterfinal.
Thursday's matchups find Argentina's seventh-seeded Juan Martin Del Potro, in his first tournament of the year after helping his homeland win the Davis Cup, meeting Bosnia's Damir Dzumhur.
Two other second-round matches Thursday will be all-American affairs, with teen star Taylor Fritz facing Donald Young and fourth-seeded defending champion Sam Querrey meeting Jared Donaldson.
