Heat put on clinic in 3rd quarter to down Celtics and take Game 1 of ECF (3:08)

In the third quarter, the Heat outscore the Celtics 39-14 to take the lead and never look back in a huge Game 1 win. (3:09)

1:37 AM ET

The Boston Celtics left their locker room at halftime in control of the Eastern Conference finals.

The third quarter happened. The Miami Heat were on their way to a 118-107 victory over the Boston Celtics after demolishing them 39-14 and using their physical superiority to send them into a death spiral of unforced errors.

It shows us what we are capable of when we worry about getting stops, getting into the open floor, getting to the free throw line, and all those good things, said Jimmy Butler, who led the way for Miami with his latest spectacular.

It reminds me that we can do it. I can see it on the paper. I lived it. I expect us to do that every quarter from now on.

That is a high bar to live up to. The Celtics played their worst quarter of the playoffs so far in the third, when Miami dominated them to the point where they played their worst 12 minutes of the playoffs so far.

Celtics coach Ime Udoka said that they were out-physicaled and out-toughed.

They definitely did.

Here are a few of the terrible statistics dredged up by that quarter.

  • The Celtics shot 2-for-15 from the field in the quarter, their worst shooting quarter over the past four seasons.

  • The Celtics went just 1-for-12 on their shots in the third after they went 15-for-28 on their shots in the first half.

  • It took Boston 7 minutes, 7 seconds to score its first basket of the third quarter, which was the longest period without a field goal all season.

  • The last time Boston took at least 7 minutes to score was in Game 3 of the 2002 Eastern Conference semifinals against the Detroit Pistons. The final score of the game? In favor of Boston it was 66-64.

  • Boston had eight turnovers as a team in the third quarter alone, and it had six turnovers in the entire quarter. The Heat scored 12 of their 19 points off Boston turnovers in the third.

Miami is up 1-0 in the series despite losing the first, second and fourth quarters.

The guys were really disappointed in the first half, according to the Heat coach. Everybody was upset with our defensive effort. This is a very good team that we are playing against. We have to do that better. They are putting a lot of pressure on our defense, which is what you expect when you get to this level.

After Boston had taken a commanding first half lead, the Heat needed to have a reversal. The Celtics appeared to carry the energy from the Milwaukee series into the first half of this game. The Celtics led by 21 points at the half. They were shooting from the field.

In the first half, Tatum had 16 paint points, which was tied for the most he had in any half in his career, as Boston dominated Miami in the paint.

Boston's collapse after the break was just as bad as the first half's, because of the horrendous third quarter. In the second half, he scored two points on 1-for-7 shooting and six disastrous turnovers. The game was tied at halftime, but the Heat got three straight turnovers and went on a 22-2 run to start the second half.

I don't want to turn the ball over and they go on runs. That is what they did.

Throughout the playoffs, we have done a great job of responding to runs after timeouts. We did not today for whatever reason. I will be the first one to take the blame. I need to lead better. I have to play better in those moments. I'm just looking forward to the next game.

Marcus Smart will be in the lineup for Boston. Smart gave the team a rousing speech on the bench to try to turn things around, but that was all he could do as he sat out with a foot injury.

Not only was Boston missing Smart, who had been questionable all day to play, but it also was without Al Horford, who was a surprise entrant into the NBA's health and safety protocols a couple hours before tipoff, and who is unlikely to return until at least Game.

Jaylen Brown said that they need to be even more disciplined. We were not prepared to be without Al and Smart. We have to be better and it is not an excuse.

We had control of the game in the first half. We lost control in the third quarter. We have to be better. I have to play better on both sides of the ball. We let the game slip away from us because we were too much of a foul. That is the story.

Information was contributed to this report.