Bradley Beal is now being dragged to court over his tiff with fans following a game against the Magic last month ... TMZ Sports has learned a lawsuit was just filed against the Wizards star on Tuesday.

In the docs, Kyler Briffa alleges he was the man who Beal got physical with during a March 21 altercation inside Amway Arena in Orlando, Fla.

Briffa says he and a friend got courtside seats to the Wizards vs. Magic tilt -- and were eventually allowed to go inside a team tunnel following the contest to interact with Washington players as they made their way into the visitor's locker room.

Briffa claims things were going fine -- until his friend made a comment to Beal about losing a bet during the game.

According to the suit, Beal "stopped, turned around, walked back toward the unsuspecting [Briffa] and without a word, intentionally struck the side of [Briffa's] head knocking his hat off of his head."

Briffa claims the hat flew "5-6 feet behind him." He then says Beal started to bully, threaten, intimidate and humiliate him in front of other fans -- which included children.

He added that he believed Beal "was attempting to provoke a physical altercation."

In the suit, Briffa says it was all finally broken up by a Wizards staffer -- who escorted the shooting guard away from the area.

Briffa says he suffered emotional distress and pain and suffering from the incident. He's suing Beal for assault. He's also suing the Wizards for negligence. He's asking for more than $50K in damages.

For Beal's part, he generally acknowledged the incident during a season-ending interview with media members earlier this month ... saying he never appreciates being heckled over gambling and betting.

Police, meanwhile, said they launched an investigation into the incident ... though no charges have been filed.