The Cavaliers edged the Celtics 105-104 at Rocket Mortgage FieldHouse.
Dean Wade scored the go-ahead basket on a dunk with 19 seconds left.
He led the team with 23 points off the bench as Donovan Mitchell missed the game due to a knee issue.
The Cavs improved to 40-and-21 and are second in the Central Division.
The team visits the Hawks tonight.