MIAMI - With shiny new diamond-encrusted rings on their fingers, the Miami Heat began their NBA title defence in confident fashion with a 120-107 win over Eastern Conference rivals the Boston Celtics on Tuesday.

Miami were presented with championship rings and rose the title banner to the arena rafters before the game to mark their second NBA title and the first since the creation of the 'Big Three' with the arrival of Lebron James and Chris Bosh to team up with Dwyane Wade.

Miami Heat players(L-R) Dwyane Wade, Chris Bosh and LeBron James react after they received their championship rings during a ceremony before the team's season opener with the Boston Celtics in their NBA basketball game in Miami, Florida, Oct 30, 2012. [Photo/Agencies]

Ray Allen made his Miami debut against his old team and put aside any concerns about his fitness with 19 points as the home crowd taunted the Celtics with chants of "We got Ray!".

Last season's Most Valuable Player James marked his first ring ceremony with 26 points but had to sit out most of the fourth quarter with leg cramps.

James, who also suffered cramps in last season's finals, left in the third quarter but came back before cramping up again.

"At that point there was no point in forcing it," said Miami head coach Erik Spoelstra.

"He already went back and started to cramp again. Game one is not the time to pull what we did in the finals," he added.

Miami Heat forward LeBron James looks to pass under pressure from Boston Celtics forward Brandon Bass during their NBA basketball game in Miami, Florida, Oct 30, 2012. [Photo/Agencies]

James' points tally continued his run of scoring at least 20 points in each of his last 28 regular season games against Boston.

Wade, looking fresh after the knee surgery in the off-season which cost him a place in the gold medal US Olympic team, top scored with 29 points, while Bosh delivered down the stretch and finished with 19 points.

Miami were 19 points up early in the fourth but, in the absence of James, Boston launched a comeback and reduced the deficit to four with just over two minutes remaining on the clock.

The Heat rallied, however, to gain a win against the team they defeated in last year's Eastern Conference championship game.

Paul Pierce had 23 points and Rajon Rondo 20 for the Celtics who are again expected to be the main challenger to the Heat in the East.

Spoelstra said he was pleased with the way his team, after enjoying the celebration, had managed to quickly put it aside and focus on the game.

"It was good to cap this night off with a win, it was emotional time for whole organisation, pre-game to raise that banner, because it brought back all the emotions and memories of how much it took to actually accomplish that collectively," he said.

"But our guys did a good job of compartmentalising and turning the switch ... and concentrating on the most important thing which was playing this game to win and giving our fans something to cheer about."

Celtics head coach Doc Rivers was disappointed with the way his time allowed Miami to take the initiative.

"I thought they were the aggressor the whole game, they got on the floor where they wanted to get, they took us out of stuff they wanted to, you can see they played together longer than us and their continuity was good," he said.