Matt Barnes and DeMarcus Cousins have just been SUED over the nightclub brawl at Avenue in NYC this week ... with the alleged victims claiming they were brutalized by the NBA stars.
TMZ Sports broke the story ... the Sacramento Kings teammates were involved in a violent altercation with two people at the VIP booth next to them around 3 AM on Dec. 5.
According to the lawsuit filed in NYC, Jasmine Besiso and Myrone Powell claim they were innocently hanging out when Barnes approached Jasmine and began to choke her.
In the suit, Powell says he saw the attack and tried to intervene but that's when Cousins stepped in and punched him in the face.
At that point, Barnes allegedly released Jasmine's neck and elbowed her in the face -- knocking her unconscious. Myrone claims he was taken to the ground and Barnes and Cousins proceeded to kick and punch him in the head and body.
The NYPD was called to the scene but Barnes and Cousins had left by the time they arrived.
A rep for the alleged victims calls the incident a "vicious and unprovoked attack" And says Cousins' initial blow was a "blindside punch."
The rep also says the two were transported by ambulance to a nearby hospital where they were treated for "serious injuries."
A rep for Barnes has previously told us that the NBA stars were the real victims -- who were attacked by the other clubgoers over an accidental bump in the VIP section.
TMZ Sports obtained video of Barnes and Cousins in the moments after the fight -- rehashing their version of what happened inside.