INDIANAPOLIS — Despite their porous record and obvious decision to tank this season because of so many injuries, the Pacers have the full respect and attention of the Celtics because of their past battles. Such as Monday’s matchup in Boston, when the Pacers couldn’t miss early, punched first, and forced the Celtics to bear down and rally.

There were plenty of scrapes in Friday’s rematch. A Derrick White bloody mouth, Neemias Queta being knocked to his knees from a questionable screen from Bennedict Mathurin, and a near-fight between Jordan Walsh and Indiana spark plug TJ McConnell late in the third quarter.

The Celtics came away wounded and fiery, but were able to pull away to a 140-122 win at Gainbridge Fieldhouse, sweeping the home-and-home series and cooling down an Indiana offense that scored 39 points in the opening period.

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The plan was to simply stay poised, continue to be offensively aggressive, then wait for the Pacers to cool off. There’s a reason why Indiana is last in the NBA in multiple statistical categories, including scoring, 3-point percentage, and overall shooting percentage.

So as Pacer shots began to clang off the rim, the Celtics stayed methodical, used a 14-point second-quarter stretch from Payton Pritchard, then spent the second half staving off any rallies and matching Indiana’s physical intensity.

“They’re a good team, regardless of their record,” coach Joe Mazzulla said of the 6-25 Pacers. “They’re always one of the toughest teams in the league and they play tough. We were able to settle down and did a great job of executing in the half court.”

While the injury riddled Pacers lack the weapons to hang with the Celtics for 48 minutes, they still have the fight of a team that reached the NBA Finals last year. Late in the third quarter with the Celtics up 24, bodies were still flying after rebounds and McConnell collided with teammate Micah Potter near the free-throw line with Walsh in the vicinity.

Celtics guard Jaylen Brown (right) recorded his eighth consecutive 30-point game.AJ Mast/Associated Press

McConnell pushed Walsh and Walsh pushed back. McConnell then charged Walsh before having to be restrained. Coaching staffs spilled on the floor, including Mazzulla, who screamed his approval for Walsh’s aggression.

“Regardless of their record or who’s playing, I think they’re constantly testing your physical and mental toughness,” Mazzulla said. “I think they’re one of the toughest teams and we have to be able to match that and do it in different ways. Any time you play them, that’s a non-negotiable. You have to be just as physical as they are. It was a great game to be a part of.”

When asked what Mazzulla said to him after the altercation, Walsh said: “He said a lot of things. He was more than happy. I’ll just put it at that.”

Walsh was assessed a technical for the pushing, but didn’t agree with the call.

“Yeah, he was mad at me,” Walsh said of McConnell. “I looked at the review. I didn’t see me push him. I thought he tripped over his teammate and then he came at me. Can’t have that. I really didn’t think he was going to do nothing. He pushes me or whatever. It’s a physical sport, two guys that are competitors. It gets like that.”

McConnell responded with two consecutive layups to spark the crowd, but the deficit was still 20 and the Celtics prevented any more suspense in the fourth quarter. Jaylen Brown posted his eighth consecutive game with 30 or more points, reaching the mark with a late flurry, while Pritchard added 29 and Luka Garza continued his resurgence with 15.

Sam Hauser, who snapped out of a slump with five triples on Dec. 19 against Miami, came back with seven Friday in eight attempts. He nailed four in a 6:42 span of the third quarter to help the Celtics maintain a comfortable lead. Mazzulla said Hauser’s teammates need to make a more concerted effort targeting him for those shots.

“It’s great when he’s making shots but it’s even better when we find him,” Mazzulla said. “I thought tonight we did a great job of hunting for him. It’s always great to see him make them but it’s great for us to be able to find him within the rhythm and flow of our offense because it unlocks the stuff that we do.”

The Celtics topped 20 3-pointers made for the eighth time this season (all wins). Hauser has converted 42.1 percent of his 3-pointers in December after making just 27 percent in November.

“You make your first couple and it’s like human nature, they’re going to try to find me a little more,” he said. “But credit to them, I wouldn’t be able to get all these open shots if it wasn’t for [Jaylen] drawing all this attention, getting to the lane, making the right read, Payton, the same thing and [Derrick] White. It’s really more credit to them, finding me and getting me the ball when I am open.”

Gary Washburn is a Globe columnist. He can be reached at gary.washburn@globe.com. Follow him @GwashburnGlobe.