Leonard methodically dribbled through the 76ers' defense and fooled forward Mike Scott and Embiid with a hesitation move before rising over the 7-footer.
Leonard leaped and threw down the one-handed jam over the outstretched arms of Embiid.
The All-Star forward finished the game with 21 points (7-of-16 shooting), 13 rebounds, four assists and two steals in the Raptors' 125-89 dismantling of the 76ers. He had scored 33 or more points in the first four games of the series.
Embiid, who battled flu-like symptoms before the game, had 13 points and six rebounds with eight turnovers.
Toronto leads the series 3-2. The Raptors can advance to the Eastern Conference finals for the second time in four seasons with a win in Game 6.
Game 6 is Thursday night at the Wells Fargo Center in Philadelphia.