Tekashi69 was stopped in his tracks at a celebrity basketball game at UCLA on Tuesday -- and the guy responsible for the encounter ... was Floyd Mayweather!!
Turns out, Floyd is a FAN of 6ix9ine -- and, while the rapper was walking around the stands at The $50K Charity Challenge taking pics with the crowd, the boxing legend approached him for a brief, friendly conversation.
You gotta see the smile on Tekashi's face when he realizes it's Floyd -- he's super stoked.
Tekashi tells Mayweather he's also a fan -- and came to the event to show him some love.
He also tells Floyd he'll hollar at him after the game.
Of course, Floyd was surrounded by a team of TMT bodyguards -- because you can never be too careful ... especially around Tekashi.