Playmate Claire Sinclair has obtained an emergency restraining order against Hugh Hefner's son Marston Hefner -- after he allegedly beat her up last night during a heated argument.
Claire just left the Pasadena Police Department, where officers interviewed her about the incident -- and we're told police granted a 3-day stay-away order against Marston to give Claire time to move her stuff out of his place.
In the video, Claire says it's a 5-day restraining order -- but law enforcement sources tell us, it's just 3.
Claire tells TMZ, she plans to move out asap -- but if she needs more time ... she'll have to go to court to extend the protective order.
Claire says she called Hugh after the incident who expressed sympathy -- claiming he was very disappointed by the situation.
TMZ broke the story ... Marston was arrested around 11:15 PM last night for misdemeanor domestic violence after police responded to a 911 call from Sinclair's family -- and observed several injuries on the model's body.
Marston -- who has been dating Sinclair on-and-off since August 2010 -- admitted the two had gotten into an argument, but didn't cop to hitting her. He has since been released on $20,000 bail.