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.

Lane Garrison says he did NOT hurt his ex-girlfriend Saturday afternoon ... but he's spending the night in jail because he's on a parole hold.

Garrison's lawyer, Harland Braun, just met with Garrison at the Beverly Hills jail. Braun says Garrison and GF Ashley Mattingly had broken up, but Garrison made a bad decision -- he went to her Beverly Hills apartment building to dog sit for his acting coach, who lives on the 3rd floor.

Garrison left the apartment unit and went downstairs to leave, but ran into Ashley in the lobby. Braun says Garrison told him ... the two began arguing about the failed relationship, and Ashley started screaming and threw Lane's cell phone against the wall. Braun says Lane then put his hands on Ashley's shoulders, put her in a chair, and then left. Lane says he did not harm Ashley.

Now get this. Lane -- who did prison time for crashing a car that killed a high school student -- is 6 days away from ending his parole. Braun says Ashley knew this and it could be her motivation for getting Lane arrested.

Braun says Ashley's injuries could have been self-inflicted.

The stakes are high for Lane. He was arrested for felony domestic violence and if the case sticks ... he could go back to prison in the manslaughter case as well as the domestic violence case.

Lane says he wants to stay in jail tonight so he can speak with detectives as soon as they come in Monday AM.

Cops went back to the Beverly Hills apartment of Lane Garrison this afternoon -- and this time the former "Prison Break" star was there ... so they arrested him on suspicion of domestic violence. 

As TMZ first reported, cops responded to a domestic violence call at Garrison's apartment yesterday ... but he was gone by the time they arrived. According to our sources, the alleged victim was Garrison's ex-girlfriend, Ashley Mattingly. 

Law enforcement sources tell TMZ the alleged victim called cops today when Garrison returned to the apartment. We're told cops arrived and arrested Garrison without incident. 

He's currently being held on $50,000 bail. 

Lane Garrison  is under investigation for allegedly hurting his girlfriend ... sources tell TMZ.

Cops won't confirm who the alleged victim is ... but we're told Lane and girlfriend Ashley Mattingly got into another big verbal blowout Saturday night. Cops got a 911 domestic violence call and responded to the scene. When  they arrived, they saw "visible marks" on Mattingly.

Sources say the verbal argument escalated to a physical brawl. 

By the time cops arrived, the former "Prison Break" star had split. Now he's under investigation for felony domestic violence.



On the video (above) ... you see Mattingly speaking to police outside Lane's apt.

Earlier in the day, Mattingly tweeted, "sooo happy to be single again from @LaneGarrison9 bye bye :) hahahaha." When someone called her out for being mean, she tweeted back, "no drunk a** is trying to brake into my apt!"

Lane has yet to speak to police about the incident.

Lane Garrison is the suspect in and alleged domestic violence incident that went down Saturday night, but when cops arrived to the scene to question him ... he was gone., TMZ has learned.

Law enforcement sources tell TMZ cops responded to Garrison's apartment in Beverly Hills but were unable to locate him when they arrived. 

According to law enforcement sources, cops took a report from the alleged victim and an investigation is ongoing.

This is the second time in less than two months cops have been called because of an alleged domestic dispute involving the former "Prison Break" star. He blamed that incident, an argument with girlfriend Ashley, on a massive misunderstanding.

Lane Garrison's Playmate girlfriend will stop at nothing to get her hands on her dead ex-boyfriend's will -- this according to the dead guy's widow ... who now wants a restraining order against the model.

41-year-old Jacqueline Rodgers filed legal docs against 25-year-old Ashley Mattingly -- claiming Mattingly ransacked her home back on February 17th looking for her dead husband's will ... just ONE DAY after he kicked the bucket.

Since then, Jacqueline claims Ashley has made repeated attempts to get back into her house to find the document -- but Jacqueline has refused to let her in. According to Jacqueline, Ashley has also sent her several harassing emails.

You'll recall -- Lane and Ashley got into a nasty fight last week over the very same guy's funeral -- because Lane was invited and Ashley wasn't ... so she got pissed and the cops got called for possible domestic violence, but no one was arrested.

Now, Jacqueline's asking the court to keep Ashley at LEAST 200 yards away from her at all times.

A rep for Ashley says the Playmate is adamantly denying the allegations ... insisting Ashley was NEVER at that house.  The rep says Jacqueline must be confusing Ashley for another woman -- her husband's girlfriend at the time he died.

Lane Garrison insists ... he did NOT beat his Playmate girlfriend Monday night during a heated argument -- telling TMZ Live, cops were called to the couple's L.A. apartment over a massive misunderstanding.

TMZ broke the story -- someone in Lane's apartment complex dialed 911, reporting a domestic violence incident in Lane's apartment. Police showed up, but no one was arrested.

Now, Lane says whoever called 911 jumped the gun -- because Lane never laid a hand on his GF Ashley Mattingly ... and she didn't touch him either.

According to Lane, the couple had been fighting loudly -- Ashley was upset Lane was invited to her ex-boyfriend's funeral and she was not. Lane believes the volume of the argument is what prompted the neighbor to call 911.

Lane added, "I just really wanted to set the record straight ... There was NO domestic violence."

The 911 domestic violence call that sent cops scrambling to Lane Garrison's apartment was triggered by a dispute between Lane and his Playboy Playmate girlfriend over who got invited to a funeral ... TMZ has learned.

As we first reported, Beverly Hills police went to Lane's house Monday night after someone in the apartment reported the incident. No one was arrested, but Lane was taken to the hospital for an unrelated medical issue.

We've now learned ... Lane's girlfriend, Ashley Mattingly, was upset that Lane was invited to her ex-boyfriend's funeral earlier in the day but she was not. It is unclear why the family of Craig Rogers made Ashley persona non grata, but we're told it triggered a heated argument between Ashley and Lane.

Ashley -- who is up for Playmate of the Year -- felt Lane should not have gone to the funeral because it showed disrespect for her.

As for the hospital visit ... sources tell us when cops arrived, Lane had a panic attack, so he was taken to the emergency room and released shortly after.

As for why he had the panic attack, we're told Lane has been vigilant about keeping his nose clean after getting released from prison in a manslaughter case. He was driving under the influence when his car crashed and killed a 17-year-old high school student who was a passenger in the car.

We're told no one was injured during the argument between Lane and Ashley. If cops had seen any trace of injury, an arrest would have been made.

Actor Lane Garrison was involved in an alleged domestic violence incident Monday night ... TMZ has learned.

Law enforcement sources tell us ... Beverly Hills police responded to a call from someone reporting domestic violence in a Bev Hills apartment.  The person who called cops was inside the apartment.

When cops arrived, they spoke with Lane and his girlfriend and wrote up an incident report.  No one was arrested, but Lane was taken by ambulance for a "medical issue" that our law enforcement sources say was unrelated to the alleged domestic violence incident.

We do not know Lane's current medical condition.

Sources tell us Lane and his girlfriend have had "issues" for a while.  As one source put it, "They've been going at each other lately."

You'll recall, Lane served prison time for manslaughter, after driving under the influence and causing an accident that killed a high school student who was riding in his car.

Lane's reps were unaware of the incident.