The Celtics, who had lost their two previous games, handed the Raptors loss. The teams have split their first two games this season.
The Raptors, who led by as many as 10 points in the third quarter, took a four-point edge into the fourth.
Image: Irving evades Kyle Lowry to score at the rim Irving made a running lay-up after a missed shot by the Raptors to give the Celtics a 92-90 lead with 7:06 to play.
Delon Wright hit a three-pointer after a Boston miss to give Toronto a four-point lead with 1:29 left.