Leonardo DiCaprio, Tobey Maguire Watch LeBron James Score 50,000th Point

Leonardo DiCaprio, Tobey Maguire and a bevy of other A-listers pulled up to the Lakers game Tuesday night and were treated to history ... as LeBron James became the first-ever NBA player to score 50,000 points right before their eyes!!

The milestone was reached in the first quarter of the Lakers' 136-115 win over the New Orleans Pelicans at Crypto.com Arena ... when James hit a 3-pointer off a pass from Luka Doncic.

DiCaprio, Maguire, Orlando Bloom and Floyd Mayweather were all just feet away from the shot ... glued to the action in their courtside seats.

They -- alongside the other nearly 19,000 fans in the arena -- cheered when the ball went through the twine ... and for good reason, because the 50K barrier might never be broken by an NBA player again.

It was certainly a great night to be an Angeleno ... as even before Bron did his thing on the court, former Lakers forward Robert Horry hosted a shootaround with some first responders and their families who helped battle the wildfires in the area earlier this year.

James told reporters after the contest he was super proud of his squad -- which is now in second place in the Western Conference standings -- explaining, "We're just meshing."