Los Angeles Lakers guard Kobe Bryant was named the NBA's Most Valuable Player on Tuesday, the first time the prolific backcourt ace has received the honour after 12 seasons in the league.

Bryant averaged 28.3 points, 5.4 assists and 6.3 rebounds a game this season for the Lakers, whose 57-25 record was the best in the Western Conference.

The 6ft-6ins (1.98 metre) Bryant, named four times to the All-NBA First Team, helped the Lakers win three successive NBA titles from 2000.

"This is a beautiful day, a special day for me," a beaming Bryant, 29, told a news conference after being presented with the trophy. "I'm just deeply, deeply honoured to be here.

"This is a team award. This is not an individual award," he added with a nod toward his team-mates, who attended the news conference.

"This gets done because we all do it as a unit and I can't thank these guys enough."

The award crowned a tumultuous year for Bryant, who last May publicly demanded a trade before reconsidering following two frustrating seasons in which he led the NBA in scoring in teams which exited early from the play-offs.

Celtics win Eastern semi-final opener

Meanwhile, the Boston Celtics shut down LeBron James to grind out a 76-72 win over the Cleveland Cavaliers in their Eastern Conference semi-final series opener on Tuesday.

Boston's defence smothered James, holding him to just 12 points and forcing him into 10 turnovers.

Kevin Garnett scored 28 points to lead the Celtics, who host Game two in the best-of-seven series tonight.