Katt Williams Punched First and Proof Is in The Video Pudding

Katt Williams can't use the "he jumped me first" excuse anymore ... because a new full and uncut video of the fight between him and a minor clearly shows the comedian struck first.

You can see Katt and the kid exchanging words while walking off a soccer field, and the jawing goes on until Katt's up against a wall. Seems pretty obvious the kid was egging on Katt, but it's also clear the comedian got physical.

Katt might still argue he felt threatened -- the kid was inches from his face -- and that's why he threw a punch.