Johnson piled up 32 points with nine rebounds, and DeRozan produced 26 points, five rebounds, five assists and three steals as the Raptors led wire-to-wire in snapping a five-game losing streak.
Kyle Lowry scored 21 points, dished off eight assists and grabbed five rebounds for Toronto, which reportedly pulled off a seven-player trade before the game.
Bryant, making his first appearance of the season for the Lakers following an Achilles tendon injury, registered nine points, eight rebounds and four assists in 28 minutes. The 15-time all-star also committed eight turnovers.
Nick Young scored 18 points off the bench to lead Los Angeles, which fell to .500 (10-10) on the season.