BOSTON -- Jimmy Butler, back after missing seven games with a sore right knee, played his first game at TD Garden since his masterpiece in Game 6 of the Eastern Conference finals back in May.

And while Butler might not have been quite that impressive in his return Friday night, he still finished with 25 points, 15 rebounds and 3 assists in 36 minutes for the Miami Heat, who survived a miraculous shot in the final seconds by Jaylen Brown to win a 120-116 thriller in overtime over the defending Eastern Conference champion Boston Celtics.

'He's such a winning player," Heat coach Erik Spoelstra said. "I feel like through the first three quarters I didn't run a play for him. He just finds a way to compete and help your team win."

It had looked like Butler had closed the door on the Celtics when he made baskets on back-to-back possessions inside the final minute of regulation -- the first coming off an assist from Kyle Lowry, and the second after he got Al Horford to switch onto him and buried a beautiful fall-away jumper with 5.6 seconds to go to put the Heat up by three.

But then, Brown came through for Boston. After taking the inbounds pass from Marcus Smart, Brown took a couple of dribbles and launched a 30-footer that careened into the basket off the backboard with 1.7 seconds to go, tying the score to send the game to overtime.

Spoelstra said he was fine with how Butler defended the play, saying he was glad Butler didn't commit a foul once Brown turned around.

"It felt good coming off my hands," said Brown, who finished with 37 points on 12-for-23 shooting. "I know we wanted to get a shot up on the rim as fast as possible just in case we missed, we can get the rebound or tip out. So when I caught it in my hand, it felt good coming off, so I let it fly."

Butler tipped his cap to Brown.

"Jaylen did what Jaylen does, and he'd been making shots all game long," Butler said. "That's tough. You got to live with that. Probably should've contested it, maybe fouled him with his back to the basket, but I just hate fouling. But he's been playing incredible, so I'm glad he made it, but I'm glad that we got the dub, so there's that."

The Heat didn't falter in overtime. Instead, they pressed their advantage and put Butler in position once again to close the door on the Celtics in the final seconds. This time, Butler made sure it would stay closed, burying a short jumper to put Miami up by four with 9.1 seconds to go.

The Celtics lost their third overtime game of the season, falling to a league-best 18-5 on the year.

"Yeah, it looked like he's got his energy, got his legs under him," said Bam Adebayo, who had 28 points and seven rebounds to lead the Heat (11-12). "And he hit some big shots down the stretch."

Miami also did a much better job on Jayson Tatum, the Celtics' All-NBA forward and MVP candidate, who went off for 49 points in Wednesday's victory over Miami. He had one of his worst games of the season Friday night, finishing with 14 points on 5-for-18 shooting.

The 14 points and five made field goals were both season-lows for Tatum, and it marked just the third time all season he has been held under 20 points in a game.

"That's the biggest thing about the league," Adebayo said. "You're not just gonna stop anybody from scoring. I feel like we are making him take tough shots every time we play him, and we live with the result."

Friday marked just the eighth time that Miami had its projected starting five available this season. And after arguably the Heat's biggest win to this point in the season, the hope within the team is that it's a start of a rise up the Eastern Conference standings.

That belief is fueled, in part, by the team's leader returning in a big way Friday night.

Butler acknowledged Friday night's thrilling win felt good.

"But we never lost confidence in the group, in ourselves," he said. "We know what we're capable of. We just have to go out there and prove it, and do it. We ain't worried about nobody else, just the guys in this locker room, coaching staff, management. We've got a long way to go, but we can get there."