Film stars weren’t the only celebs battling it out last night! A showdown between famed music moguls Madonna and Sean “P. Diddy” Combs heated up into a friendly discussion over which artist reigns the music kingdom. “Diddy and Madonna were yelling at each other about who has a bigger impact on the music world,” an insider told OK! about the joking scene at Madonna and Guy Oseary’s annual late night post-Oscar party.

Madonna and Diddy were taking jabs at each other “in a funny way,” according to the insider, “but still yelling.”

And to cap the whole thing off with some fun? “Madonna and her dancers all had a dance-off in the middle of the party!” the source tells OK!.

Both artists are pioneers in their own way — The Material Girl vs. Bad Boy For Life!

Madonna must have ended the dispute, as she will soon be taking on a new role as a referee.