The Celtics were constantly targeting Robinson on defense and he was trying not to be a victim. Miami had been hammered by the Celtics, 143-110, on Jan. 25, and it was trying to avoid another embarrassment on national TV by playing a gritty, physical game. The Heat succeeded. But the Celtics held them scoreless for 1 minute, 40 seconds down the stretch and out-gritted the Heat.

And while the teams aren’t scheduled to meet again this season, this is almost an inevitable playoff matchup, and both sides walked away with even more disdain for each other. Brown was sending a message.

“Yeah, I’m OK with [the flagrant],” he said. “There was no issue for me. I think he knew what he was trying to do, trying to get tangled up, etc., because he didn’t want to play defense. They called the foul but he was still trying to hang on so I was trying to get my arm free.”

Said Robinson: “I thought it was a dirty play to be honest with you. That’s how people miss entire seasons. Guys suffer really bad injuries from instances exactly like that. I don’t know how he’ll justify it. I told him, ‘we’re both locked up.’ Obviously he took it to another place.

With Marcus Smart and Grant Williams gone, the Celtics have been accused of lacking enforcers. On this occasion, Brown enforced himself. Boston is 13 games ahead of Miami in the standings and the Heat are going to have to fight to avoid the play-in tournament. This could be a first-round matchup, and the Celtics know they are a better team and can’t get sunk by Miami’s mesmerizing mental schemes that have worked magnificently before.

The Celtics were quite open about their feelings on the Heat.

“Miami’s known for being physical; Miami’s known for getting away with a lot of that stuff, kind of mucking up the game,” Brown said. “You’ve got to protect and own your space. Duncan Robinson knew what he was doing there, trying to get tangled up, trying to draw whatever . . . I don’t know what he was trying to do. I bet you he won’t do it again.

Porzingis — who punished the Heat with 25 points, 9 rebounds, and 2 blocks, and is proving to be unguardable by Miami — said the altercation between Robinson and Brown was welcomed.

“When they got into it again, I kind of liked it, it got the whole crowd into it, it was a good atmosphere,” Porzingis said. “I love it. I think we have to take those emotional moments in a good way, make us fired up, controlled. We have to stay controlled because that’s their game. They need us to react to something.

“They have to do that to mix up the game, making something happen. We have to be smart in those situations but show that we’re right there. They want to beat us as much as we want to beat them. It was a war. It was fun. We came out with a win and proved who we are.

The Celtics led for the final 38 minutes, 5 seconds but they knew the Heat were going to keep charging, even when they lost Josh Richardson (shoulder) and Terry Rozier (knee) to injuries during the game. Miami’s spiritual leader, Jimmy Butler, missed Sunday because of death in the family.

It didn’t matter that the Heat were shorthanded. The Celtics relished the challenge of mastermind Erik Spoelstra with his unorthodox zone defenses and malleable lineups as he tries to compensate for an offense that is bottom five in scoring and field goal percentage.

The Celtics obviously have more talent than Miami but they have also boosted their toughness. They welcomed the playoff-style atmosphere and the physical play and responded with physicality of their own. Jayson Tatum got the best of Bam Adebayo on a key possession in the final minute, stripping the ball away twice before he muscled Haywood Highsmith away to secure the sealing rebound. There was nothing pretty about that play, it was nothing but grit.

“Today was fun and we have a lot of history with this team,” Tatum said. “That [expletive] was just fun, it was fun to be out there. We have to be a team that punches and matches and exceeds their physicality.

The Celtics did that Sunday, and they’ll need to keep that mentality into June.