Paris Hilton was left fuming after her younger brother Barron, 24, was beaten bloody by one of Lindsay Lohan's friends.

Hilton was at a all-night party at a mansion on Miami's Star Island Thursday night, which was also reportedly attended by Lohan. The troubled actress got word that the hotel heir had said some nasty things about her and confronted him with a friend, who proceeded to rearrange his face.

Hilton claims he was jumped after she told him, "You talk s**t about me to my boyfriend, this is what you get." He also says that Lohan watched the beatdown while laughing.

according to,Lohan denies that she was at the party, and her father, Michael also added that there were witnesses to attest that she wasn't involved in any altercations at the party -- but video footage acquired by the site proves otherwise, as Hilton is seen confronting Lohan shortly after he was beaten.

Hilton was advised to seek medical treatment following the injuries, and he checked in to an area medical center Friday night to get a CT scan to make sure there wasn't any internal bleeding or other major internal injuries.

He posted an image of his face on Instagram from the hospital, and big sis Paris commented on the photo, writing, "They both (Lindsay and her friend) will pay for what they did. No one f***s with my family and gets away with it!!"

Sister Nicki also addressed the incident on her twitter page, writing, "Bad things happen when you hang out with bad people."

A police report was filed after the incident and an investigation is underway.

The two families have had bad blood between them since 2006, when Paris' friend Brandon Davis referred to Lohan as a "firecrotch," among many other things.

It's on now!