Azealia Banksand Angel Haze went at it in 2013. After the former friends had a spat on Twitter over a perceived slight, Angel released a diss track, "On the Edge." Azealia fired back with "No Problems," which Haze matched with "Shut the F-- Up." The peace flag was never waved, although both seem to have moved on.
(Photos from left: Tullio M. Puglia/Getty Images, John Ricard / BET)