Offset reacted to a guy spraying champagne -- which might have splashed Cardi B -- by delivering some cham-pain ... in the form of a wild punch off the stage.
The husband and wife rappers were partying after 3 AM at Booby Trap On the River strip club in Miami, and were standing on stage next to a pole when the champagne started flying.
We're told Cardi got wet and wasn't thrilled about it, but Offset was enraged and immediately began looking for the guy. As you can see, once he spotted him, Offset wound up his fist and let it fly.
People at the club tell us the punch landed, and Offset kept throwing 'em until he was pulled off by security. We're told he and Cardi took off immediately after that.
It's pretty crazy, because both Cardi and Offset performed at David Grutman's LIV nightclub in Miami Beach earlier Thursday night ... kicking off a series of events this weekend leading up to Sunday's big game.
The vibes seemed to be all good, and the couple also seemed to have a great time when they first arrived at Booby Trap. Cardi danced on Offset, and he made it rain on her.
Obviously, things changed for the worse later on.
The strip club dust up came a day after Offset was detained in an L.A. shopping center. We broke the story ... Offset was released from jail after a few hours and told us cops had the wrong guy.
Two men in Offset's group were ultimately booked on firearms charges, though.