If you needed another reason to hop on our “TMZ After Dark” tour (and trust, we’ve got plenty) — Justina Valentine gave the ultimate sales pitch by turning the weekend into a full-blown rager!

The ‘Wild N Out’ rapper totally owned the crowd … freestyling wild about everyone on the party bus — like a private concert on wheels.

Check out the full vid … Justina even dropped a bar about Ray J, who made a special — and shirtless — guest appearance during this night out in Hollywood.