Miami's LeBron James looks at his Championship ring.

Miami's LeBron James looks at his Championship ring. Photo: Getty Images

LeBron James received his long-awaited NBA championship ring on Tuesday, then he and the Miami Heat launched their bid for another with a season-opening 120-107 victory over the Boston Celtics.

While the Heat were busy signalling their intentions of maintaining their supremacy, the revamped Los Angeles Lakers failed to fire in a 99-91 loss to the injury-depleted Dallas Mavericks.

Defensive force Dwight Howard, who arrived as part of a four-team trade in August, had 19 points and 10 rebounds, but fouled out and was a dismal 3-of-14 from the foul line in his Lakers debut.

Steve Nash, a two-time Most Valuable Player also acquired in the off-season, finished with seven points and four assists.

Pau Gasol led the Lakers with 23 points and Kobe Bryant, playing despite a sore foot that had kept him out of practice for nearly a week, added 22.

But they couldn't stop a Mavericks team missing German star Dirk Nowitzki, who is still recovering from arthroscopic knee surgery.

Miami were in celebratory mood, with players receiving their rings and fans cheering as they raised their title banner to the rafters.

The Celtics did their best to spoil the party, but the star triumvirate of James -- who missed much of the fourth quarter with leg cramps -- Dwyane Wade and Chris Bosh along with newly acquired former Celtic Ray Allen proved too much Boston.

James scored 26 points with 10 rebounds. Wade added 29 points, Bosh scored 19 with 10 rebounds and Allen chipped in 19 against his former team.

"King" James is coming off a spectacular season, earning Most Valuable Player honours in the regular season as well as the NBA Finals triumph over Oklahoma City before helping the US Olympic team win gold in London.

He departed the game late in the third quarter with cramps, returned early in the fourth and made a long-range jump shot to give the Heat their biggest lead of the night, then exited again.

"Once you start cramping, there's nothing you can do about it," James said.

Paul Pierce scored 23 points and Rajon Rondo added 20 points and 13 assists for Boston, but the Heat's suffocating defence held the Celtics without a point over the final 2:09.

Not all of the night's emotion was of the feel-good variety. Wade was angered by a late foul by Rondo, who seized Wade around the neck in a move Wade called a "punk play".

Only one other game was on the opening night slate, with the Cleveland Cavaliers holding on for a 94-84 victory over the Washington Wizards.

AFP