Lil Wayne jumped on stage during Drake's concert Sunday night and made it clear ... his beef with Birdman is what almost got him to throw in the rap towel.
Drake was super supportive of Wayne during his Houston concert, but it was Wayne who got the crowd riled up by taking a shot at Birdman, who's refused to release "The Carter V" for years. Wayne, who's in an epic legal battle with Birdman, ended with a call to action ... "F*** Cash Money!"
Drake made his support clear after the concert, saying, "We are fighting until you get yours. Freedom to drop music and peace of mind." Drake added this ... "I know you gave me a shot and all I can ever do with the rest of my life is return the favor. YOUNG MONEY FOREVER."