Lane Garrison's ex-GF claims the actor hit her so hard Saturday she got a giant knot on her head.
Garrison was arrested Sunday for felony domestic violence. The incident occurred at Ashley Mattingly's Beverly Hills apartment the day before, when the two began arguing and it turned physical.
Mattingly says the problems started Friday when they went to the Playboy Mansion and Garrison got wasted and began "hovering over Hef." She says Garrison slept in his car that night, came back to her apartment Saturday and that's went the real trouble started.
Mattingly says in addition to the knot, she has multiple bruises. She also says she'll press charges IF Garrison refuses to go to rehab.
As for Garrison, his lawyer tells us the actor denies hurting Ashley, claiming she went ballistic and he merely put her in a chair to calm her down.