Precious Achiuwa had 15 points and 15 rebounds, and Fred Van Vleet had 11 points and nine assists for Toronto, which lost its first game to the Wizards.
In the home debut of new Boston coach Ime Udoka, Jayson Tatum scored 18 points and Al Horford came back for a second stint with the Celtics to add 11 points and 11 rebounds. Jaylen Brown, who scored a career-high 46 points in a season-opener double overtime loss to New York on Wednesday night, had nine points on a 3-on-13 shot.
Toronto was leading 59-51 when Tatum was whistled for a technical foul, and the free throw made it a 10-point game. The call appeared to energize the Celtics, who scored the next three baskets to cut the deficit to two points.
But they failed to score the next five moves on the floor – never to shoot three of them. The Raptors scored 10 straight points – including six by Trent – and 20 of 23 to take an 80-61 lead.
As Brown notched a personal best in Game 1, Tatum managed a shot outside the night making just 7 of 30 shots – 2 of 15 at 3 points. Tatum was 8 of 14 against Toronto, but Brown missed all seven attempts by 3 points.
Pacscal Siakam missed both Toronto games as he returned from offseason left shoulder surgery.
Udoka made his home debut as the 18th manager in franchise history. Horford returned after missing the opening following a positive COVID-19 test. Dennis Schröder played 23 minutes and had four points, four rebounds and four assists.
HAPPY TO SEE YOU AGAIN
Marcus Intelligent thanked the crowd before the game. The Celtics also introduced former players in attendance, including the recently inducted Hall of Famer Paul Pierce and recently retired team president Danny Ainge.
It was the first full-participation regular-season game at TD Garden in 593 days since March 8, 2020, before the NBA shut down due to a pandemic. The building unveiled a new dashboard with video screens almost twice the size of the old ones at a resolution that officials say is better in the NBA or NHL.
Raptors: Host Dallas on Saturday.
Celtics: See you in Houston on Sunday.
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