VIDEO: ERYKAH BADU I Know Rappers, and ... YOU'RE NO RAPPER, IGGY AZALEA!

Just when Iggy Azalea thought it was safe to leave home ... Erykah Badu hit her with a ton of shade while hosting the Soul Train Awards.

Erykah opened the show by taking a slight shot at herself -- pointing out that hip-hop fans give her crap for making rappers "change gods and wear crochet hats" (see Andre 3000) ... but it was all a setup for this shot at Iggy.

Check it out ... the crowd loved it, but it'll be a while before Iggy sees the sun again. Just so much shade.

"Invest in the brand!"