Jennifer Hudson at BET Awards -- Pays Off Prince Threat ... Look Away, Madonna (VIDEO)

BET did a lot of trash talking about Madonna's tribute to Prince ... and Jennifer Hudson had to back it up by performing that same song. No pressure.

You'll recall ... the BET Awards called out the Billboard Awards for its tribute to Prince -- featuring Madonna and Stevie Wonder singing "Purple Rain." As they put it on Twitter ... "Yeah, we saw that. Don't Worry. We got you."

Sunday night, J. Hud had to put up or shut up ... check out her performance.

Who sang it better?