Antonio Brown Pleads Not Guilty, Acted In Self-Defense, Attorney Claims

Antonio Brown's fighting back against claims he tried to shoot and kill someone at a celebrity boxing match earlier this year, pleading not guilty to 2nd degree attempted murder ... an incident his attorney is adamant was nothing more than self-defense!

AB hired Mark Eiglarsh ahead of his trial ... and the lawyer sent TMZ Sports a statement addressing the altercation at Adin Ross' event, explaining he took the case because he "passionately believes in Brown's defense."

"The actions he was forced to take were solely in self-defense against the alleged victim's violent behavior," Eiglarsh said. "Brown was attacked that night and acted within his legal right to protect himself from an individual who had previously committed criminal acts against him. It's a privilege to represent him, and I am determined to ensure that justice is served."

On Monday, Eiglarsh entered a not-guilty plea on Brown's behalf.

As we reported ... Brown was extradited from the United Arab Emirates last week, and sent back to the United States. The 37-year-old former NFL superstar is currently in New Jersey, awaiting a ride back to South Florida.

Shortly after the mid-May incident, we spoke with the alleged victim, Zul-Qarnain Kwame Nanatambu ... who told us Antonio snapped at him before trying to shoot him with a handgun.