Eyewitnesses tell TMZ the former boxing champ was in South Beach at around 9 PM Saturday, walking with fellow boxer Gervonta Davis, when he jaywalked on busy Collins Avenue and a driver honked at him. We're told Adrien got angry and smacked the hood of the car and began yelling at the driver.

Cops were already out in force because it's Spring Break, they heard the commotion and warned him to calm down or else he'd be arrested. We're told Broner then started yelling at the police so they cuffed him for a time but did not arrest him.

Broner didn't let the incident dampen his night. He went to Exchange Miami nightclub where he did the Bust Down dance and even jumped onstage.

Earlier this week Broner threatened to attack and even shoot gay people in a vile video posted to his social media account. He said, "If I got my gun on me, I'm shooting you in the f***ing face, and that's on God and them ... I don't like gay sh*t." The comments were directed at social media star Andrew C. Caldwell, the famous "I'm Delivert" guy. Caldwell had said Broner was flirting with him. Broner's response was to "punch the testosterone out you GAY ASS."