Lil Wayne -- I Didn't Spit On Ref, But I Got Up in His Grill for Cheating (NEW VIDEO)

Lil Wayne's face off with a referee in a charity hoops game was definitely violent -- we've got new video to prove that -- but Weezy denies ever unloading a loogie on the guy.

As we reported ... Wayne lost his temper when the ref repeatedly made calls against his Young Money squad during the recent game in St. Louis. Sources close to Tunechi tell us he went after him dead set on starting a fight.

In the clip, you clearly see him charge at the ref and try to slap the whistle right out of his mouth. But we're told Wayne didn't spit on him. There's no evidence of it from this angle, although the ref does towel off his face at one point.

Funny moment in the vid -- as the melee erupts, someone yells ... "No! We can't do this two times in a row!!" We think he's referring to the promoter, Loose Cannon Slim's last attempt at a St. Louis stop the violence event.