Jennifer Hudson Battles It Out With Jennifer Holliday

It's the battle of the Jennifers!

Jennifer Hudson shocked the audience at her and Robin Thicke's concert last night in Atlanta with a surprise jaw-dropping sing-off against Jennifer Holliday with—what else?—"And I'm Telling You (I'm Not Going)."

Holliday first made the song famous—and her signature tune—when she sang it eight times a week in the original 1981 Broadway production of Dreamgirls.

And then Ms. Hudson introduced it to a new generation...

J.Hud's powerhouse rendition in the 2006 movie adaptation of the musical helped snag an Oscar for the silver screen newbie.

So who do you think does it better? Let the diva disagreements begin.

Meanwhile, Holliday wasn't the only one joining Hudson onstage. She and fellow American Idol-er Fantasia performed their Grammy-nominated song "I'm His Only Woman."

Make sure to take a gander at Ms. Fantasia. She's definitely going to be looking svelter than ever on her new VH1 reality show—girl has lost some major poundage.