EXCLUSIVE

Miami Dolphins linebacker Koa Misi raised hell at a Florida nightclub -- knocking down a clubgoer with a massive strike to the head ... before trying to run from the scene, this according to the police report obtained by TMZ Sports.

The report was filed by a Ft. Lauderdale police officer -- who says he was working a detail at Cyn Nightclub around 3:41 AM on Sunday morning when he witnessed Misi and some friends get into an altercation with another group.

FYI, Misi is in the middle of a 4-year $17 MILLION contract.

The cop says it appeared as if the parties were going to separate and leave -- but "Misi and other members of his group charged toward the nightclub entrance [at the other group]."

The cop says "I witnessed Misi strike [the victim] in the head, causing him to fall to the ground."

Then it gets crazier ...

The cop says, he was able to "force" the 6'4", 250 lb linebacker to the ground and told him to sit in place while he tended to the victim.

But Misi allegedly blew off the officer's orders and tried to run ... that is, until super cop "executed a leg sweep to bring him to the ground."

MISI GOT COBRA KAI'D!!!!!

The officer says several of Misi's friends tried to pull him away and help him escape -- but the cop was able to fight them off until additional cops came and helped him handcuff Misi.

The victim was loaded up into an ambulance -- but told cops he did NOT want to press charges.