Trailing by seven points with 7 1/2 minutes remaining, Young sparked a 20-6 Sixers run to finish the game, handing Philadelphia its third straight victory.
Jason Richardson posted 21 points while Jrue Holiday supplied 19, 12 assists, eight rebounds and three steals in the triumph.
The Sixers' Thaddeus Young also netted 10 points during the fourth quarter, ending with 18 overall to go with seven boards.
The Raptors, meanwhile, fell to 1-5 on the road despite a combined 46 points from DeMar DeRozan and Andrea Bargnani.
Jose Calderon helped out with a double-double of 13 points and 12 assists for Toronto.