A vicious "Love & Hip Hop: Atlanta" brawl has triggered a lawsuit ... which now alleges one of the stars was smoking crack cocaine at the reunion show.
Althea Eaton has filed suit against Joseline Hernandez, who is caught on tape punching Althea in the face and dragging her to the ground ... then hitting and scratching her for good measure.
In the suit, Althea claims eyewitnesses allegedly observed Joseline smoking crack cocaine out of a pipe backstage during the show. Althea believes Joseline was high as a kite when she attacked.
It's interesting ... Althea is NOT suing the show or the network, which means one of 2 things:
1. Producers didn't orchestrate the fight
2. They did but she needs the job