After Payton Pritchard raced onto the court again with time running out and drilled a buzzer-beating 3-pointer to end the third quarter Monday night, Bucks coach Doc Rivers slumped over with his hands on his knees and looked as if he had just eaten a bad meal. meatball.

It was an image that best captured the damage the Celtics have inflicted on opponents this season, creating an apparent mix of frustration, helplessness and discomfort. Rivers said he circled Pritchard’s name on a dry-erase board Monday morning, emphasizing to his players that he is a “game-changer.”

But it’s becoming increasingly clear that no matter what warnings opponents get, no matter what they do, these Celtics are inevitable. Boston didn’t play a perfect game, but it wore Milwaukee down and earned a 119-108 victory at TD Garden, pushing its record to 4-0.

“We are still learning, building and growing,” Jaylen Brown said. “Definitely some things we’ve seen over the last few games that we can clean up. Even in the first half of this match I thought we weren’t playing at our level. That’s part of the season, a new journey, and it’s about us. It’s a mental battle every night to do our job and do it well.”

Brown led Boston by 30 points, Pritchard hit 8 of 12 three-pointers and scored 28 points off the bench, and Jrue Holiday added 21 points against his former team. Damian Lillard had 33 points and Giannis Antetokounmpo added 30 points and 10 rebounds for the Bucks.

There was a time not too long ago when Milwaukee was viewed as the Celtics’ most fearsome competition in the East. But this summer, as teams like the Knicks and 76ers bolstered their rosters, the Bucks were more or less stuck.

They came into this game with puzzling losses to the Bulls and Nets, and gave no indication that they were in position to pull off an upset. But at least they fought for about three-quarters of the time. Then the Celtics used a bad call as a source of motivation when things looked shaky.

With 2:42 to go in the third, Holiday’s attempt grazed the rim as the shot clock wound down, but it was ruled a shot clock violation. The Celtics had already won two challenges and had no more, and when they expressed their displeasure with the call from the bench, they were whistled for their second stoppage of play, resulting in a technical foul.

Lillard’s ensuing free throw gave Milwaukee an 80-79 lead. Fans groaned, the Celtics gestured and it felt like a turning point. That’s why coach Joe Mazzulla said he instructed his players to create as much chaos on the field as possible.

“I just felt like this was the environment that was needed at that time,” Mazzulla said. “It was just: creating chaos. So we’re just going to create it. And then we just created the chaos together, went through the chaos together and responded pretty well. Because no one had any idea what was going on, right? Just chaos. Yes, it’s perfect. It’s exactly what we needed.”

With Mazzulla still chirping at a referee on the sideline, Jayson Tatum played tough, aggressive defense against the bigger Bobby Portis and forced a trip. At the other end, the 6-foot-2 Pritchard fought for an offensive rebound that led to a Derrick White 3-pointer.

White then added three more before holding his ground against the powerful Antetokounmpo in the paint and knocking away a shot. The chaos increased and the Celtics became energized.

“I think injustice always makes us feel like we can be superheroes,” Holiday said. “But yes, I think there will be weak or bad decisions during matches. How we respond to it, or how we responded to it tonight, we responded very well.

After White missed a three, Jordan Walsh, who provided a spark from the bench, slid in behind Antetokounmpo and converted a putback.

Pritchard then finalized the increase in the third quarter. As the Celtics prepared to get the ball out from under Milwaukee’s basket with 6.5 seconds left, a fan shouted, “Give it to Pritchard!” Most people in the arena were probably thinking the same thing.

Rivers said he begged his players not to let Pritchard move to his right during these late clock situations, but Pritchard found room to move to his right. He took seven quick and powerful dribbles before finally firing a shot through the net from the right arc, sending the crowd into a frenzy.

The one-point deficit after the technical foul had turned into a 90-82 lead. The Celtics then started the fourth quarter on a 7-0 run and largely remained in control from there.

“Payton is a killer and he is always looking to put pressure on a defense,” Brown said. “If you don’t put pressure on him and guard him, he will set you on fire.”

Adam Himmelsbach can be reached at [email protected]. Follow him @adamhimmelsbach.