Prosecutors have hit Tony Ferguson with a charge of DUI after he allegedly wrecked his truck in Hollywood last month, TMZ Sports has learned ... but we've also learned the UFC star is already fighting back in the case, pleading not guilty to the misdemeanor.
The 39-year-old entered the plea at his arraignment last week ... less than a month after authorities say he crashed his pickup truck into two parked cars outside of a Hollywood club just before 2 AM.
The scene was terrifying ... the truck ended up on its side following the collision -- though, somehow, no one was injured.
UFC Fighter Tony Ferguson Arrested for DUI After His Truck Flipped Over
At the time, law enforcement sources told us Tony had refused to take a field sobriety test and was "very uncooperative" at the scene. They also said cops who eyeballed him claimed he reeked of booze and had bloodshot eyes.
Ferguson is due back in court for another hearing on the matter later this month.