LiAngelo Ball has a slam dunk with his new song "Tweaker" ... and he's getting a big seal of approval from DJ Paul.

We got the Three 6 Mafia rapper at LAX and our photog asked him about Gelo's debut single.

DJ Paul says the beat reminds him of '90s rap ... telling us its further evidence the '90s are making a huge comeback, in music and in fashion.

LiAngelo -- the only Ball brother who is not balling out in the NBA -- has a future in rap and is already getting invited to perform at Coachella ... and DJ Paul isn't ruling out a collab in the dessert ... because his group is playing the famous music festival too.

"Tweaker" is getting lots of play on social media and in the sports world -- the Detroit Lions bumped it in the locker room after winning a division title -- and LiAngelo's gotta feel good about DJ Paul's reaction here.

The guy's produced tracks for some of the biggest acts in hip hop ... so his opinion carries major weight.