MIAMI — The Boston Celtics exited their locker room at halftime Tuesday evening answerable for Recreation 1 of the Japanese Convention finals.

However then the third quarter occurred. And, after the Miami Warmth demolished the Celtics, outscoring them 39-14 and utilizing their physicality to ship Boston right into a demise spiral of miscues and unforced errors, the Warmth have been on their technique to a 118-107 victory to take the opening recreation of this best-of-seven affair.

“Greater than something, it simply reveals us what we’re able to each time we fear about getting stops, stepping into the open ground, attending to the free throw line, all these good issues,” mentioned Jimmy Butler, who led the way in which for Miami along with his newest spectacular efficiency in these playoffs, ending with a game-high 41 factors — together with 17 in that decisive third quarter — 9 rebounds and 5 assists in 41 minutes.

“It simply jogs my memory, we will do it. I see it on this piece of paper. I lived it. So I count on us to do this each quarter from right here on out.”

That is a excessive bar to stay as much as. Miami pummeled Boston into submission within the third to the purpose the place the Celtics performed not solely their worst 12 minutes of those playoffs thus far — however one of many worst quarters Boston has had, interval.

“[We] acquired out-toughed, out-physicaled,” Celtics coach Ime Udoka mentioned. “They appeared like they got here out within the second half and wished to up their physicality and aggression on each ends, and so they did that.”

They definitely did.

This is a sampling of the disastrous statistics dredged up by that quarter:

• The Celtics shot 2-for-15 from the sphere within the quarter, their worst capturing quarter over the previous 4 seasons, both common season or playoffs.

• After Boston went 15-for-28 on contested pictures within the first half, the Celtics went simply 1-for-12 on them within the third.

• The 7 minutes, 7 seconds it took for Boston to attain its first basket of the third quarter was Boston’s longest drought to start out 1 / 4 and not using a discipline purpose all season.

• The final time Boston took a minimum of 7 minutes to attain in 1 / 4 was Recreation 3 of the 2002 Japanese Convention semifinals versus the Detroit Pistons. The ultimate rating of that recreation? It was 66-64, in favor of Boston.

• Jayson Tatum had six turnovers within the third quarter alone, and Boston had eight as a staff — as many because it had within the different three quarters mixed. The Warmth additionally scored 12 of their 19 factors off Boston turnovers in that third.

All of it was sufficient so as to add as much as the truth that, regardless of shedding the primary, second and fourth quarters, Miami finds itself up 1-0 on this collection.

“The fellows have been simply actually disillusioned at halftime,” Warmth coach Erik Spoelstra mentioned. “I barely wanted to say something. Everyone was simply disillusioned at our defensive effort and focus. However look, this can be a superb staff that we’re taking part in in opposition to. So it is not solely us saying that, hey, we now have to do this higher. They’re placing numerous strain on our protection, and that is what you count on once you get to this stage.”

The Warmth wanted to have that form of reversal after Boston had managed the primary half with relative ease. Coming off a seven-game slugfest with the defending champion Milwaukee Bucks — a collection Boston closed out in emphatic trend on its dwelling courtroom in Recreation 7 — the Celtics appeared to hold that momentum into the primary half of this recreation. The Celtics staked themselves to a 62-54 first-half lead, led by 21 factors from Tatum. They shot 59% from the sphere.

In that first half, Tatum had 16 paint factors — tied for essentially the most he is had in any half in his profession — as Boston outscored Miami 42-24 within the paint.

However simply as Tatum’s play was emblematic of Boston’s robust first half, his horrendous third quarter was a logo of Boston’s absolute collapse after the break. Tatum scored two factors on 1-for-7 capturing within the second half, along with these six disastrous turnovers within the third quarter. Miami acquired three straight pick-6 turnovers it was layups or dunks that blew the sport open as a part of a 22-2 run to start out the second half that gave the Warmth the lead for good.

“I feel clearly I do not need to flip the rattling ball over and s— like that,” Tatum mentioned. “However I suppose all through the course of a recreation, issues occur, and so they go on runs. That is what they did.

“All through the course of the playoffs, we have achieved an excellent job of responding to runs after calling timeout, issues like that. However for no matter purpose we did not immediately. I will be the primary one to say I will take the blame for that. I’ve acquired to steer higher. I’ve acquired to play higher, particularly in these moments. I am simply trying ahead to responding subsequent recreation.”

Boston will hope to reply in Recreation 2 with Marcus Good within the lineup. Good gave the staff a rousing speech on the bench to attempt to flip issues round after that ugly third quarter, however that was all he may do as he sat out with a proper midfoot sprain.

Not solely was Boston lacking Good, who had been questionable all day to play, however it additionally was with out Al Horford, who was a shock entrant into the NBA’s well being and security protocols a pair hours earlier than tipoff, and who’s unlikely to return till a minimum of Recreation 3.

“We have got to be much more disciplined,” Jaylen Brown mentioned. “Clearly, we weren’t ready to be with out Al. We positively weren’t ready to be with out Al and Good. It is not an excuse; we have to be higher.

“We nonetheless had management of the sport within the first half. We misplaced management within the third quarter. We have simply acquired to be higher. Bought to play higher on either side of the ball, extra self-discipline. We fouled fully an excessive amount of, and we let the sport slip away from us. That is the story.”

ESPN Stats & Info contributed to this report.