The Boston Celtics claimed critical home-court advantage and a 3-2 series lead in the Eastern Conference Finals, earning a gritty 93-80 Game 5 win against the Miami Heat on Wednesday.

In all four quarters the Celtics held the Heat to 23 points or fewer, but the offensive side of the ball was also far from clicking early on.

The Heat led 19-17 at quarter-time and after winning the second frame 23-20, they held an incredibly low-scoring 42-37 lead at the long break.

In the first half, both teams shot under 39 per cent from the field and 26 per cent from three-point range, but the Heat were winning the physical battle on the boards, pulling in nine offensive rebounds to just two for the Celtics.

The two teams also combined for just six fast-break points in the first half, illustrating the slow, grinding pace of play as both defences locked in, forcing better ball and man movement.

Back in Game 1, also in Miami, the Heat who came out of the locker room for the third quarter and went on a rampage to swing that game, but this time the shoe was on the other foot.

The Celtics doubled up the Heat in the third period, winning it 32-16 as Jayson Tatum, Jaylen Brown and Al Horford found rhythm on the offensive end.

Boston led 69-58 after three quarters, and extended that lead to 23 points in the opening minutes of the final frame, as Brown knocked down three big triples.

After a first half where he was the subject of plenty of criticism for his loose ball handling – with four first-half turnovers – Brown made the difference after half-time, finishing with 25 points on 10-of-19 shooting and five-of-nine from long range. He also had no turnovers in the second half, and the biggest dunk of the game.

Jayson Tatum was also at his playmaking best, with 22 points on a mediocre seven-of-20 shooting, but he added 12 rebounds and nine assists, consistently creating opportunities for shooters off the dribble and showing advanced ability to make reads as play unfolded.

The real story of the Celtics' success was their ability to take away the three-point line for the Heat, though.

With Jimmy Butler's jump shots not falling – finishing with 13 points on four-of-18 shooting – Miami simply had no avenue to reliable outside scoring.

The Celtics' ability to chase hard over the top of screens and dribble hand-offs made life miserable for Max Strus and Duncan Robinson, taking away their catch-and-shoot opportunities and turning them into dribblers, far outside their comfort zones. 

Strus finished zero-of-nine from the field, missing all seven of his three-point attempts, while Robinson was four-of-12, including three-of-10 from long range. As a team, the Heat were just seven-of-45 (15 per cent) from beyond the arc.

Instead, the Celtics dared the Heat to beat them inside, banking on the stoutness of their terrific interior defensive duo of Horford and Robert Williams III. That pairing combined for 17 rebounds, five blocks, two steals and just one foul.

Game 6 will head back to Boston, meaning the first-seeded Heat need to win on the road to save their season and force a Game 7.

The Boston Celtics will receive a big boost for their crucial Game 5 clash against the Miami Heat on Wednesday night, with Defensive Player of the Year Marcus Smart returning to the line-up.

Smart missed Game 4 after suffering an awkward ankle injury in Game 3. 

Adding to the Heat's problems is the fact that Sixth Man of the Year Tyler Herro will not return for Game 5, having not recovered from the groin strain that also kept him out of Game 4.

With each side missing one of their key players, the Celtics were buoyed by the performance of backup point guard Derrick White, who posted a handy stat-line of 13 points, eight rebounds, six assists and three steals in his first start since missing Game 2 for the birth of his child.

White's performance – especially on the defensive end – will likely cement his position in the rotation above fellow bench guard Payton Pritchard as Smart returns to the equation.

On the other side, it was Victor Oladipo shining off the bench as he tried to fill Herro's shoes, with the former All-Star scoring 18 of the Heat's first 28 points in Game 4, going on to finish with 23 points, six assists and four rebounds. 

He also had a plus/minus of plus four from his 30 minutes, meaning the Celtics won the 18 minutes he was off the floor by 24 points.

Game 6 will head back to Boston on Friday, before a potential Game 7 back in Miami, if required.

Erik Spoelstra has no doubt the Miami Heat can inflict the sort of brutal defeat that the Boston Celtics doled out in Game 4 as the Eastern Conference Finals heads towards its climax.

A 102-82 loss in Boston on Monday night came on the back of Miami scoring a trifling 11 points in the first quarter, with Jimmy Butler scoring just six points all night and no Heat starter reaching double figures.

The visitors shot just 33.3 per cent from the field (30 of 90), with Boston's win squaring the series at 2-2 and setting up Game 5 in Miami on Wednesday evening as a pivotal occasion.

Coach Spoelstra said: "More than anything, our offense really hurt us at the beginning. They weren't getting the sort of purposeful execution that you need to on the road. [Boston] were able to get some relief points from that and get to the free-throw line. They did a better job of getting into us and rotating guys into the paint."

It was 57-33 by the halfway mark, and Spoelstra admitted the Heat simply failed to ignite. Yet he says Miami can swiftly set the game aside and dominate the next time the teams meet on court, saying it would not surprise him if the tables are turned.

"We've got guys that love these kinds of moments, the playoffs. You've just got to stay together," Spoelstra said.

"This is part of the playoffs. There are these extreme highs and lows, a lot of emotion. You just have to stay the course, stay together. What you're looking at is a great series. It's 2-2. You have to embrace that. Hopefully this competition beings out the absolute best in all of us.

"They got the best of us tonight. We'll take this hit and then get to Miami and get ready for Game 5. Whatever they have done to us, we can do to them."

Jayson Tatum led Boston with 31 points. The Celtics led by 32 points at one stage before Miami began to claw back the deficit late on.

"We're not making any excuses. They outplayed us tonight, for sure," said Spoelstra.

Jayson Tatum never doubted himself after a poor Game 3 performance, returning to a starring role as the Boston Celtics dominated the Miami Heat 102-82 in Game 4.

The Celtics had their backs to the wall in the latest tussle of the Eastern Conference Finals, with the threat of heading back to Miami for Game 5 trailing 3-1, but they made sure it was not a nervous night for the Boston faithful.

Derrick White – returning to the starting line-up after the birth of his son – started in place of the injured Marcus Smart and scored the first seven points, kick-starting a 26-4 run to open the game.

The Celtics defense proved to be immense, holding the visitors to just 42 points with less than three minutes remaining in the third quarter.

Eleven first-quarter points also set a new record for the Heat's worst offensive first quarter in any playoff game in their history.

After only scoring 10 points in Game 3, Tatum responded in fine fashion, racking up a team-high 31 points on eight-of-16 shooting, hitting 14-of-16 free throws, while adding eight rebounds, five assists and two blocks.

Speaking later, Tatum highlighted the confidence he has in his ability, despite how dark things can get immediately following a painful loss.

"Right after it's tough," he said. "You're frustrated with how you played, knowing how important this time of year is, and feeling like you let your team-mates down.

"But I think I do a really good job of sleeping it off – regardless of if I have 10 points or 46 points – the next day is the next day, and whatever happened, happened.

"Obviously I was ready to get back to playing, but I didn't doubt myself – I know how to play basketball.

"Regardless of how many points I score, [it's about] just trying to come out and help us get a win. That's most important."

With the series now tied at 2-2, Tatum called it "a new series", but he stressed his side need to bring the same intensity after a win, as opposed to just after crushing losses.

"It's 2-2 – it's kind of like a new series, a best-of-three," Tatum said.

"Human nature plays a part in [the swings in the series]. When you win a game, you can relax a little bit, but obviously when we lose a game, we feel like the next game is do-or-die, and then we come out and play how we did.

"We need to have that mindset going into Game 5 – it is a must-win game – and tonight was essentially something like that. Everybody knew it, we could all feel it, and I think it showed with the way we came out."

When asked if he enjoyed sitting out the fourth quarter after clocking 117 minutes across the first three games of the series, Tatum said: "It was extremely nice – especially because we were winning."

Celtics coach Ime Udoka made sure to highlight the efforts of White after he finished with 13 points, eight rebounds, six assists and three steals.

"He checks so many boxes for us, it's not only things that show up on the stat sheet," Udoka said.

"He's the guy that moves the ball very well, defends extremely well, multiple positions… I couldn't be more happy with him being here, and what he brings to this team."

Udoka touched on what it will take to come out on top in this series, echoing Tatum's sentiments about bringing the same intensity after a win.

"Our mindset was right coming out, we came out with the right physicality and focus," he said. "We've just got to muster that same energy when we're coming off a win, as well as a loss.

"It wasn't our best offensive night, but defensively, obviously we were elite tonight, for the most part.

"We've got room to grow still, that's the thing with us, and we can always rely on our defense. We've won several games doing that this year when our shots aren't falling.

"To hold them in the 30s for basically three quarters, it's high-level defense.

"We can do that even if our shots are not falling, it's mainly about taking care of the ball, not letting them get anything easy, and kind of wearing on them mentally."

After Game 5 in Miami, Game 6 will head back to Boston, with a potential Game 7 to be played in Miami, if required.

The Boston Celtics smothered the Miami Heat all night on the way to a 102-82 victory in Game 4 of the Eastern Conference Finals.

With the win, the Celtics evened the series at 2-2, and are still yet to lose back-to-back games this postseason. 

It all started on the defensive end for Boston, playing in front of their raucous home fans, as the Heat missed their first 14 field goal attempts.

The Celtics led 29-11 at quarter time – after leading 26-4 at one stage – marking the fewest first-quarter points ever scored by a Heat team in the playoffs. They shot three-for-20 from the field.

Victor Oladipo tried to ignite the Heat off the bench, scoring 18 of their first 28 points, but it was a historically bad showing from Miami's starting line-up, made even worse by the fact Sixth Man of the Year Tyler Herro was out injured.

With three minutes remaining in the third quarter, the Heat trailed 73-42, leading to their starters getting benched for the final frame. Their five starters combined to score 18 points and shoot seven-for-38 (18 per cent) from the field.

For Boston, Jayson Tatum was terrific, scoring 24 of his 31 points in the first half, finishing up with shooting figures of eight-of-16 from the field and 14-of-16 from the free throw line.

The big-man combination of Al Horford and Robert Williams III was also game-changing, as the duo combined for 22 rebounds and six blocks, while Derrick White also shined in his first game since becoming a father.

White missed Game 3 for the birth of his child, and after scoring no more than nine points since Game 4 of the Celtics series against the Milwaukee Bucks, he had 10 points in the first quarter as he started in the place of the injured Marcus Smart.

He went on to finish with 13 points, eight rebounds, six assists, three steals and a blocked shot.

Game 5 will head back to Miami with plenty on the line. Throughout NBA history, when a series has been tied 2-2, the winner of Game 5 goes on to win the series 82 per cent of the time – although the Celtics bucked that trend last round.

Tyler Herro will miss Game 4 of the Eastern Conference finals, but the Miami Heat are hopeful Jimmy Butler will face the Boston Celtics on Monday.

Herro sustained a groin injury during the Heat's 109-103 Game 3 win and will play no part as Miami attempt to take a 3-1 lead at TD Garden.

Heat head coach Erik Spoelstra said: "We just had to be responsible and take the decision out of his hands.

"He really wants to be out there tonight. The trainers and Dr. [Harlan] Selesnick don't think that's the best idea just because of the intensity and everything, but we'll see.

"He's young, we'll treat him day-to-day, and we'll see what happens from here."

Butler has been suffering with inflammation of his left knee, but will warm up with the intention of playing in Game 4.

Spoelstra is also hoping Kyle Lowry (left hamstring strain), Max Strus (right hamstring strain), P.J. Tucker (left knee irritation) and Gabe Vincent (left hamstring strain) will feature.

Celtic trio Jayson Tatum (stinger), Marcus Smart (sprained ankle) and Robert Williams III are listed as probable.

Jimmy Butler will not require an MRI scan after leaving Game 3 of the Eastern Conference Finals with knee inflammation, said Miami Heat coach Erik Spoelstra, who praised Bam Adebayo for "stabilising" the team in his absence in a 109-103 win over the Boston Celtics.

Butler played 19 minutes in the first half but did not emerge from the locker room for the second at TD Garden.

Yet the Heat were still able to claim a 2-1 lead in the series, a rematch of the 2020 Eastern Conference Finals in the NBA Bubble, thanks predominantly to Adebayo.

Adebayo went 15 for 22 from the field as he scored 31 points and added 10 rebounds.

He also had six assists and four steals. The Heat's 19 steals marked a franchise postseason record and the most for any team in a playoff game since 2015.

Having produced 32 and 27-point games against the Celtics in the bubble, Adebayo's three-highest scoring playoff performances have now all come versus Boston.

"He did his version of what Jimmy does in terms of 'do what's necessary for the game,'" Spoelstra told a media conference of Adebayo, who finished plus-17 in the plus-minus.

"He was extremely assertive, it happened in a lot of moments that were fully in the context of how we want to play. He was just way more assertive on the catch and those moments in between. 

"It wasn't just the scoring, that's what everybody is going to recognise but he did so many things in terms of getting us organised, facilitating, playing point guard for us at times, running offense in the post through him and then defending as he always does one through five against a team that presents a lot of challenges.

"He's a winning player. He really is the heart and soul of our group, you can count on him all the time, he doesn't get caught up in all the noise, he's just out there competing, playing winning basketball, doing it on both ends and doing what is necessary.

"When Jimmy was out in the second half he just stabilised us. It got a little bit gnarly out there and when it did we were able to get the ball to Bam and just get something coherent."

The Miami Heat warded off a gritty fightback from the Boston Celtics to win 109-103 on Saturday, reclaiming home-court advantage and taking out Game 3 in the Eastern Conference Finals.

The Celtics were down by 26 points in the first half and clawed their way back to make it a one-possession game down the stretch, but clutch baskets from Max Strus and Bam Adebayo were able to halt momentum.

Erik Spoelstra's side eventually saw the game out from the free-throw line.

With Jimmy Butler and Tyler Herro off injured in the second half, Adebayo finished with 31 points on 15-of-22 shooting, 10 rebounds, six assists and four steals in a big performance.

Jaylen Brown led the late charge for the Celtics, scoring a game-high 40 points off 14-of-20 shooting from the floor, but turnovers were critical as the team failed to take care of the ball.

Brown was responsible for seven of his own while Jayson Tatum and Marcus Smart combined for 10 with the Celtics committing 23 turnovers.

Boston shot 37.5 per cent from three-point range but following a 39-14 first quarter, were facing an uphill battle.

The Heat scored 33 points off those turnovers in contrast to Boston's nine points, with double-digit margins for points in the paint (48-34) and bench points (26-16).

Butler came up with eight points and three rebounds as well as two assists and steals, but knee inflammation saw him miss the second half. 

Kyle Lowry's return to the floor was pivotal for the Heat, however, finishing with 11 points, six assists and four steals.

Jimmy Butler said the Boston Celtics "whipped our tail on our home floor" in their 127-102 beatdown of the Miami Heat in Game 2.

The return of Defensive Player of the Year Marcus Smart from a foot injury ignited the Celtics on the offensive end just as much as defensively, with the team hitting a red-hot 20-of-40 from three-point range.

Boston's five that played at least 30 minutes – Jayson Tatum, Jaylen Brown, Grant Williams, Al Horford and Smart – shot 17-of-29 from long-range, and combined for 23 assists, which was two more than Miami had as a team.

Speaking to post-game media, Butler said the Celtics "tried to embarrass us", but pointed out that they were always going to be facing an uphill battle against such an outlier shooting performance.

"You do have to move on, but I don't like to move on from this. It has to hurt," he said.

"They tried to embarrass us – they did embarrass us. I think we got to realise that, or use it as fuel, but realise that the game can get out of hand when you're playing against a really good team like them that can score the ball and get stops.

"They made shots that they missed last game. That's just what it is.

"It's going to be hard to beat anybody when they shoot 50 per cent from the field and 50 per cent from three. They were the more physical team overall, and they got one on the road.

"Overall, we just have to be better. We've got a tough job to do to go over there and win, but if they did it, we can do it as well."

He added: "I look at it as 'it can't get too much worse'. They whipped our tail on our home floor.

"I guess if they do it on their home floor it's supposed to happen, but I don't see us doing that again. 

"The first half has been brutal for us in both of these games, we just got to come out and play harder from the jump and be ready, because they be throwing some haymakers in the first half."

Heat coach Erik Spoelstra said he did not feel like his side played poorly – but that it felt like the Celtics wanted revenge for Game 1.

"You definitely have to credit Boston," he said. "It's not just that they came in with great urgency and physicality – they did have that, for sure – they also played well. They played really well on both ends.

"We know what they're capable of defensively – they've done this to some very good offenses. I'm sure they were not happy with us putting up 118 in Game 1, and they came out very disruptive. 

"They got us out of our normal rhythm and flow, and the shot-making on the other end was very tough to overcome.

"You get to this point – in the Conference Finals – you just have very good teams. Teams without many weaknesses, it's great competition.

"This only counts as one, and that's what the experiences players and staff in the locker room understand. We don't like it, but they played extremely well."

Boston Celtics coach Ime Udoka believes his side responded well to being "punked" by the Miami Heat, claiming a 127-102 win in Game 2 of their playoff series on Thursday.

A 39-14 third quarter in the Heat's favour effectively decided Game 1 as the Celtics collapsed on the road, but bounced back, cutting down turnovers and putting four quarters together to split the first two games in Miami.

Marcus Smart and Al Horford's returns to the line-up were critical for the Celtics as they claimed home-court advantage against the Eastern Conference's first seed, but it was a collective effort with 28 assists off 43 made field goals.

Udoka praised his side's mental toughness in responding against a side that came at them in the opening game of the series.

"I think we were upset with how that third quarter went, specifically how we got out-toughed," Udoka said post-match. "Wasn't a lot of schemes or defensive or offensive changes, they just came at us and kind of punked us in that third quarter.

"We looked the other three quarters and how well we had done in winning those quarters, and knew if we just matched their physicality, we could be better. It kind of reminded us of Milwaukee a little bit – the first game – and didn't want to get caught off-guard again.

"I think our guys have bounced back really well all year, especially the second half of the year. Haven't lost two games in a row in a while, and obviously having Marcus and Al back gave us a little boost as well."

Smart was an important figure in his return from a foot injury, filling the stats sheet and finishing with 24 points, 12 assists, nine rebounds and three steals.

Horford provided a little bit of everything meanwhile, ending the game with 10 points, three assists and rebounds as well as a steal and a block.

Udoka commended the returning duo, allowing the team to capitalise on positive aspects from the first game.

"It was great to have the vets back, obviously," he said. "A calming presence there. We didn't get off to our best start, we were a little slow to start but we fought right back into it.

"After, I guess, the first five or six minutes we held them down scoring-wise, but it was a good overall effort. I felt we didn't play as poorly as the last game showed.

"Like I said, we won three quarters and had a very bad third quarter, it was hard to overcome but we saw a lot of positives and areas we could attack."

The Boston Celtics rebounded from a disappointing Game 1 to thrash the Miami Heat 127-102 in Game 2 on Thursday.

With the win, the Celtics have tied the series at 1-1 and snatched home-court advantage, with Game 3 and Game 4 to take place in Boston.

In arguably their best half of the season, the Celtics were nearly flawless to open the game, shooting nine-of-11 from three-point range in the first quarter on the way to putting up two consecutive 35-point frames, leading 70-45 at half-time.

The Heat threatened to make things interesting in the third period as Jimmy Butler piled on 16 of his game-high 29 points but the Celtics had an answer every time, shooting 20-of-40 from three for the contest, including 17-of-29 from the five Boston players to play more than 30 minutes each.

Jayson Tatum finished with a team-high 27 points on eight-of-13 shooting with five rebounds and five assists, while Defensive Player of the Year Marcus Smart had 24 on eight-of-22 shooting with nine rebounds, 12 assists and three steals.

Jaylen Brown chipped in an efficient 24 points on nine-of-17 shooting, and Grant Williams was excellent once again for the Celtics with 19 points off the bench, shooting five-of-seven from the field, and was +37 in plus/minus over his 32 minutes. Only Payton Pritchard finished with a higher plus/minus, finishing plus +39 in his 23 minutes, scoring 10 points with two assists in Derrick White's absence.

After dominating the 2020 Eastern Conference Finals against the Celtics, averaging over 20 points per game on 60 per cent shooting, Bam Adebayo had his second straight disappointing showing. After posting 10 points and four rebounds in Game 1, he followed it up with just six points and nine rebounds. 

Adebayo is averaging 14 points and seven rebounds in the playoffs thus far, significantly down from his season averages of 19 points and 10 rebounds.

Jimmy Butler has assured he will sustain intensity against the Boston Celtics, following the Miami Heat's 118-107 win in Game 1 of the Eastern Conference Finals on Tuesday.

Butler was at his best for the Heat, finishing with 41 points on 12-of-19 shooting, nine rebounds, five assists, four steals and three blocks.

He also took 18 free-throw attempts and only two three-point attempts in comparison, attacking the basket at almost every opportunity.

Against a Boston team that can be just as physical and aggressive as the Heat, the six-time All-Star said he will thrive on it, but the individual stat line does not matter in relation to wins and losses.

"I like physicality. I want to run into people and see who falls down first, who's going to quit first," Butler said. at the post-game news conference.

"I think that's the style of basketball I like to play and so do they. I was zero-for-two from three tonight, I want to go zero-for-zero next game, because I just want to keep banging into people.

"I think I speak for my teammates, the Miami Heat organisation when I say I know what I'm capable of. I don't do this, score 40 points, I play the way that I play to win, by all means necessary. It just so happens that I scored 40, but if I score 40 and lose I'm gonna be really pissed off.

"I have so much trust in my teammates and I will continue to play that way. I've been a quote unquote scorer at other points in my career, and it didn't work out too well for me, so I'm glad that I have the guys that I have around me and with me."

Down by eight at the start of the second half, the Heat turned it around with a 39-14 third quarter in which they were able to get six steals and force the Celtics to none-of-seven from the perimeter.

Butler's 17 points and three steals as the Heat turned Game 1 around were critical, but he asserted that the team knew they needed to dial up the intensity on the defensive end before coach Erik Spoelstra even addressed them.

"It's crazy because he [Spoelstra] didn't have to say too much," he said. "We already knew what we were doing wrong – turning the ball over, not getting back. We're at home, we've got to play better basketball, as a team. We did that, went on a little run, but this was just a win.

"I've said it all season long, whenever we let our defense dictate our offense, we're a much better team – we get stops, get into the open floor, we whip that ball around to our shooters and that's the style of basketball we call Miami Heat basketball. Gritty, dog-like, worried about getting stops instead of worried about getting buckets."

Boston Celtics forward Jayson Tatum has taken the blame for his turnovers in the Miami Heat's game-changing 22-2 third-quarter run in Tuesday's Conference Finals Game 1 defeat.

The Celtics led 62-54 at half-time but were blown away by the Heat in a staggering 39-14 third quarter where Boston gave up eight turnovers, including six from Tatum.

Boston were not helped by poor shooting offensively, with their two-of-15 (13 per cent) from the field in the third being their worst in any quarter over the last four seasons.

"They were down at half-time and came out and played hard in the third quarter," Tatum told reporters after the game.

"It's on me, I had six turnovers. I've got to take care of the ball better, especially in those situations when they're going on runs like that."

Celtics head coach Ime Udoka said his side lost their composure during the third quarter, with Jimmy Butler starring for the Heat at both ends.

Butler finished the game with 41 points, including 27 in the second half, while he also had four steals and three blocks.

"They looked like they came out in the second half and wanted to up their physicality and aggression at both ends," Udoka said.

"I don’t think we obviously responded well on either end of the floor. We had eight of our 16 turnovers in that quarter.

"It flipped very quickly. We lost our composure."

The win gives the Heat a 1-0 series lead but Udoka was eager to point out that the Celtics won three of the four quarters, offering hope moving forward.

"We won three quarters other than that but obviously that one is going to stand out, 39-14 on two-of-15 is tough to overcome," he said.

"We won the transition battle, won the second-chance points battle we won the points in the paint, really had one poor quarter that hurt us.

"It was strictly from a physically standpoint. It wasn’t anything different that they did. At least we bounced back in the fourth."

Jimmy Butler scored 41 points including 27 in the second half as the Miami Heat's third-quarter charge helped them to a 1-0 lead in the Eastern Conference Finals with a 118-107 win over the Boston Celtics on Tuesday.

After trailing 62-54 at half-time, the Heat went on a 22-2 run early in the third quarter to storm ahead and never looked back from there. The Heat are 7-0 in the 2022 playoffs at FTX Arena.

Butler's 41-point haul was his sixth time in 12 playoff games where he has hit the 30-point mark. It was also his third 40-point night of these playoffs.

The Heat forward shot 12-of-19 from the floor, along with eight-of-11 in the second half, while he also had nine rebounds, five assists, four steals and three blocks in a remarkable all-round display.

Butler becomes the first player this postseason with at least 30 points and four steals in multiple games.

Gabe Vincent (17 points, three assists, three blocks), Max Strus (11 points including three triples, four rebounds, two assists, two steals) and Tyler Herro (18 points, eight rebounds, three assists) all provided good support.

The Celtics were left to lament their 39-14 third quarter, along with their 11-of-34 three-point shooting, cooling off in the second half.

Boston's two-of-15 (13 per cent) third-quarter field goal shooting was their worst in any quarter over the last four seasons. The Celtics only managed four points in the paint in the second half, having scored 42 in the first.

Jayson Tatum top scored for Boston with 29 points with two-of-nine from beyond the arc along with eight rebounds, six assists and four steals.

Jaylen Brown added 24 points, 10 rebounds and three assists, while the absence of Marcus Smart (foot) and Al Horford (health and safety protocols) was felt.

The Heat were also missing veteran point guard Kyle Lowry due to a lingering hamstring issue.

Miami's 12 blocks for the game, led by center Bam Adebayo (10 points, four rebounds, four blocks), was a joint franchise playoff record.

The Boston Celtics have lost Al Horford and Marcus Smart for Game 1 of the Eastern Conference Finals against the Miami Heat.

Horford will miss out after entering the NBA's health and safety protocols, while Smart has a right mid-foot sprain, the team said.

Losing center Horford and point guard Smart just hours before the series opener is a major blow to head coach Ime Udoka.

It remains to be seen how long the pair must stay sidelined. Both played significant roles in Boston edging out the Milwaukee Bucks in a semi-final series that went to a Game 7 decider on Sunday.

Speaking before the twin absences were announced, Udoka said the Celtics would look to make a strong start against Miami, despite lacking time for a breather between series.

Udoka said: "We didn’t get a ton of rest, as opposed to Miami, who had a few days off. But we're riding some momentum and staying sharp and there's benefits to that as well. Miami got [four] days off, but as far as what we did against Milwaukee, some carryover could be good."

Boston are not alone in being without key personnel. It had previously been announced Miami guard Kyle Lowry will miss Game 1 with a hamstring injury.