Lindsay Lohan Masterminds Barron Hilton Beat Down?

Lindsay Lohan accused of setting up Paris Hilton's little brother Barron for a beat down.

Paris Hilton's little brother Barron Hilton was jumped this morning -- and beaten to a pulp -- and he claims Lindsay Lohan masterminded the attack, TMZ has learned.

We know Lindsay's denying she ordered the hit -- in fact, she claims she wasn't even on the scene at the time of the incident -- but now we have video (above) that proves otherwise. It shows Barron (blonde hair, white shirt) and his friends confronting LiLo right after the attack.

Multiple sources connected to the situation tell us ... Barron attended a party last night at a Miami mansion where Lindsay has been staying while she's in town for an art festival -- a party that lasted until well after the sun came up.

We're told ... during the party, someone accused Barron of talking smack about Lindsay -- and a short time later he was attacked and beaten to a pulp. TMZ obtained a photo of the damage.

Jacked from TMZ