We're told ... Wayne believed the bottle-thrower was a member of Maidana's entourage (the fighter's trainer) -- who was following close behind -- and Weezy immediately tried to confront the guy to fight it out.
You can see in the video ... a member of Wayne's entourage grabbed the rapper and kept him from getting into it ... though it's clear, Weezy was heated.
At one point, you can hear Wayne scream at Maidana's camp, "Let's GO, n***a!"
Ultimately, both sides were separated without further incident.