's family threw down in a massive drunken brawl as violent as any wrestling cage match -- with ripped shirts, bloodied faces, and her daughter Bristol getting dragged around a lawn by her legs.
The brawl went down last month near Anchorage, Alaska ... when the Palin clan -- Todd
and his kids Willow
, and Bristol
-- went to a friend's house party. According to the police report ... obtained by TMZ ... the violence erupted when Bristol went after a woman who had allegedly shoved her younger sister Willow.
Bristol told police the homeowner, Korey Klingenmeyer
, shoved her to the ground, dragged her around, and started calling her a slut and a c**t.
Korey and several other witnesses at the party saw it differently ... telling cops Bristol punched him in the face -- he says he let her hit him 5-6 times before grabbing her fist and pushing back ... sending her reeling to the ground.
That scrap then sparked the all-out brawl -- witnesses say Track and 3-4 other people came running to defend Bristol ... and all hell broke loose ... with the Palins, including dad Todd, taking on all comers.
Willow says several people at the party we're chanting, "F**k the Palins!"
One witness says Todd got jumped by 4 people, and Track jumped in to help his father. He emerged from the scrum with a torn shirt and bloody mouth. Bristol says she was uninjured, though one cop described her as having "dirt on her knees."Worth nothing ... cops described almost everyone at the party as being "intoxicated" ... including the Palins.
As for Sarah ... the report says she was sitting in a limo outside the party. She's not mentioned at all in the fight -- but it sounds like she tried to calm things down after the fact. The homeowner, Korey, did not want to press charges. In fact, prosecutors declined to file charges against any of the 20-plus involved in the melee.
Not surprisingly, Korey told cops the Palins lost the fight. We've reached out to the Palins ... so far no response.