DeMarre Carroll scored 11 points and Bismack Biyombo had 14 rebounds as Toronto improved to 8-2 at home this postseason.
Game 5 is Wednesday night in Cleveland.
Cleveland lost consecutive playoff games to an Eastern Conference opponent for the first time since dropping the final three games of the conference semifinals to Boston in 2010.
LeBron James scored 29 points and Kyrie Irving had 26 for the Cavaliers. Channing Frye scored nine of his 12 points in the fourth quarter.
