But It's Not a Shot at Jussie

WE ARE THE CHAMPIONS!

Abel Osundairo was proudly rocking a red MAGA hat while celebrating a big moment in his boxing career ... but he says he's not throwing a jab at Jussie Smollett.

Ya gotta see this video TMZ obtained of Abel and brother Ola celebrating Abel becoming the top amateur boxer in his weight class ... they're partying it up at a Chicago club, with some eye-catching hats.

Abel's got a red hat that says MAGA ... which, of course, plays like a reference to Jussie claiming his attackers yelled "this is MAGA country" during the hoax attack.

While some think he was gloating over Jussie, who was just found guilty of lying to Chicago cops, Abel's attorney, Gloria Rodriguez tells TMZ ...…