Jaylen Brown, Derrick White power Celtics past Cavaliers 120-95 in Game 1

In the final seconds of the third quarter Tuesday night, Payton Pritchard corralled a rebound, zigzagged past the logo and launched deep, contested 3-pointer.

As the ball fell through the net, everyone’s hands at TD Garden shot up in unison. On a night where the Celtics controlled the tempo throughout but couldn’t pull away initially, Pritchard’s hoist proved to be the dagger.

The Celtics took a commanding 15-point edge into the fourth, extended it to 22 a few minutes in and cemented a 120-95 victory over the Cavaliers in Game 1. Jaylen Brown led the way with 32 and Derrick White added 25, but it was a balanced performance.

The Celtics ensured Cleveland’s momentum from Game 7 against Orlando – and Boston’s six days without a game, for that matter – wasn’t a factor. Boston, with Paul Pierce, Mike Gorman and other celebrities in the house, systematically wore the Cavaliers down and eventually overpowered them in the second half.

Brown came out with an aggressive mind-set, using the upfake to his advantage and burning the Cavaliers from inside and out. He scored nine points early, helping the Celtics built a 12-2 edge in the opening minutes.

Donovan Mitchell (33 points) and the Cavaliers stormed back, using a 21-9 flurry to pull ahead, 23-21. The Celtics’ defensive intensity wasn’t where it needed to be midway through the quarter. Enter Luke Kornet.

Kornet used his length to alter shots at the rim on one end and thrived as a screen-setter and space-filler on the other. The Cavaliers placed so much attention on Jayson Tatum (18 points) and Brown (for good reason) that Kornet was often the beneficiary under the rim.

He helped the Celtics turn a 25-25 tie into a 40-34 lead through one. Brown finished the quarter with 15 points – his only miss coming on a half-court heave at the buzzer. The Celtics shot 54.2 percent, moved the ball well and consistently generated high-quality looks. The only problem for Boston was that Cleveland shot 50 percent from 3-point range and looked far too comfortable at times.

Both teams ratcheted up the defensive intensity in a sleepy and somewhat sluggish second quarter, as the pace shifted and each side chucked up a string of misses.

Celtics coach Joe Mazzulla turned to a double-big lineup of Al Horford and Xavier Tillman Sr. Tillman, who logged just seven total minutes in the Heat series, flummoxed the Cavaliers in the paint.

Neither side found much a of a rhythm, but Tatum continued to do a bit of…