Raonic's 6-3, 6-4, 6-2 defeat of Garcia-Lopez at Thunderbird Sports Center provided Canada with an insurmountable 3-1 advantage in the best-of-five first-round Davis Cup series.
The Canadian banged out 22 aces against the Spaniard, who was tabbed to replace Marcel Granollers in the match.
Canada now advances to April's semifinals. There they will play Italy, which defeated Croatia earlier Sunday.
Beautician charged with giving client fatal silicone butt injection
Attkisson leaves CBS News, reportedly over network's 'liberal bias'