Dallas had kept alive their title hopes with a 122-84 win on Friday to deny the Celtics a clean sweep in the best-of-seven championship series.
But in front of their home fans in Boston, the top seeds were inspired to victory by Jayson Tatum’s 31-point performance.
The championship win was the Celtics’ first in 16 years and moves them one clear of the Los Angeles Lakers, who have won 17, in the record books.
It was miserable night for Dallas’ Kyrie Irving, who left the Celtics in 2019, as he was heckled by the crowd and scored only 15 points.
The Celtics were strong from the start and led 67-46 lead at halfway, with Irving and Doncic restricted to just 14 points between them in the first quarter.
Dallas rallied slightly in the latter stages of the third quarter but still could not find a way past the Celtics, who took a 19-point advantage into the final quarter.
https://emp.bbc.com/emp/SMPj/2.52.1/iframe.htmlMedia caption,
Boston Celtics Jayson Tatum says team have ‘reached the top of the mountain’
Jaylen Brown named NBA Finals MVP
In front of the jubilant crowd at the TD Garden in Boston, Jaylen Brown was handed the MVP trophy, which is named after Celtics’ legendary centre Bill Russell.
He put in a strong defensive display against Dallas’ Luka Doncic – the regular-season top scorer.
Brown, 27, averaged 20.8 points, 5.4 rebounds and 5.0 assists in five Finals games.
“It was a full team effort,” said Brown, who signed a five-year contract extension with the Celtics worth $286m (£225m) last year.
“I share this with my brothers and my partner in crime Jayson Tatum – he was with me the whole way, so we share this together.”
Brown, who has not been selected for the US Olympic basketball team for the Paris Games this summer, said he remained positive Celtics could overcome their previous Finals disappointments.
“I never hung my head,” he added.
‘Celtics find a way to get job done’ – analysis
Sam Harris, BBC Sport Journalist
With the best regular season and a fine play-off run, the Boston Celtics have earned the right to hang banner 18 in the rafters.
Their Finals performance had a hiccup in game four with a blowout loss, but they found a way to get the job done at home.
The triumph is the culmination of a lot of hard work from a team who have developed a strong mentality, and the result too of some bold front-office decisions.
At the forefront is franchise star Jayson Tatum, who has faced intense scrutiny and criticism during his bid to end a long personal wait for a championship.
Now that criticism is silenced. The 26-year-old embraced a new role in this series, showcasing his playmaking skills and leading the team.
You cannot mention one franchise star without the other, and Jaylen Brown also deserves significant credit – acting as the series’ momentum controller.
The Celtics have a tendency to build huge leads, then let their opponents claw their way back – a habit that reappeared in this series.
However, Brown’s silky handles, clutch shots, and explosive drives ensured that, game four aside, the Mavericks could not overhaul them.
The winning mentality has not just been shown on the court. After the Celtics lost the 2023 Eastern Conference final to the eighth-seeded Miami Heat, head of basketball operations Brad Stevens made huge calls to trade for both Jrue Holiday and Kristaps Porzingis, two players who have been pivotal to Boston’s success.
Throw Derrick White and Al Horford into the mix – it is a championship-winning recipe.
Gone is the element of fear that plagued previous play-off match-ups against stars such as Stephen Curry and Jimmy Butler.
While there are habits head coach Joe Mazzulla will aim to refine to sustain this level of success and build a potential dynasty, for now Boston sit atop the NBA as the champions.
The Celtics can revel in their achievement, knowing they have earned their place as kings of the hill.