A Nicolas Cage fan says Mötley Crüe rocker Vince Neil literally busted her ass when he attacked her on the Vegas Strip for absolutely no reason ... according to her.
Kelly Guerrero says she and her son were walking down into the Aria Hotel and Casino and recognized Nic Cage, hanging with Neil and Carrot Top. She says they complimented Cage on his career, particularly for "Ghost Rider" and "City of Angels."
According to the lawsuit she's now filed ... Guerrero says that's when Nic put Vince in a headlock during what she called "horseplay." She says when Vince got free he suddenly attacked her, grabbing her hair from behind and yanking her to the pavement.
She says the beating was brutal ... leaving her with neck pain, low back pain, a hip injury and a fractured tailbone.
TMZ got video shot immediately after the alleged incident ... where Nic attempted to get an apparently drunk Vince into a car outside the Aria.
Guerrero described Vince as being drunk or under the influence, and claims he attacked another woman too. He's been criminally charged with misdemeanor battery.
She's suing for $150k ... minimum.