Six Celtics scored in double figures, led by Jaylen Brown with 27 points, as Boston dominated the Toronto Raptors 111-89 on Monday night to take a 3-2 lead in their best-of-seven Eastern Conference semi-final series.
Kemba Walker added 21 points, Jayson Tatum had 18 with 10 rebounds, Brad Wanamaker and Daniel Theis scored 15 apiece and Marcus Smart 12 for the Celtics, who rebounded from two consecutive losses after they had blown a 2-0 lead in the series.
Boston will get the chance to clinch their place in the conference finals berth with a Game 6 victory on Wednesday night.
Fred VanVleet had 18 points to lead the Raptors, who never led in the contest and trailed by as many as 30 points.
The Celtics ran away early as the Raptors endured one of their worst scoring playoff quarters in franchise history. Boston were up 18-5 after eight-and-a-half minutes as Toronto began 2-of-14 from the field.
The Raptors ended the quarter shooting 4-for-20 and they trailed 25-11. They hit one of nine shots from three-point range.
Boston's advantage reached 46-25 on a Tatum three-pointer with 4:55 to go in the second. The lead reached 28 points before half-time and the Celtics entered the break up 62-35 after Walker beat the buzzer with a floater.
Brown led Boston with 16 first-half points, Tatum added 12 and Smart and Wanamaker each had 10. Meanwhile, no Raptors players were in double figures.
Toronto shot 13 of 43 (30.2 per cent) in the half and 4-of-18 from three-point range (22.2 per cent). The 27-point half-time deficit tied the largest ever faced by a defending NBA champion during a playoff game, according to STATS.
The Raptors began the third with a 6-0 run, Pascal Siakam making a trio of short-range buckets, but the Celtics' lead never dropped below 20 in the quarter. At 4:23, Boston's advantage reached 79-49 on a Brown step-back jumper.
The Celtics led 87-63 after three and the Raptors emptied their bench by midway through the fourth.
For the game, the Celtics outshot the Raptors 49.4 per cent to 38.8 per cent. Boston hit 24-of-27 free throws while Toronto made 11-of-13.