Fantasia shows up, too! Scroll down to view both performances

*Fans at Thursday's Atlanta stop of the Jennifer Hudson/Robin Thicke tour got a special treat when Hudson brought Jennifer Holliday on stage for a sing-off of the song that brought both of them critical acclaim - "And I'm Telling You (I'm Not Going)."

Holliday made the song famous when she sang it eight times a week in the original 1981 Broadway production of Dreamgirls. Hudson's version in the 2006 movie adaptation propelled her toward an Oscar win.

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

Check out both performances below. And be sure to listen up for their "male" admirers in the audience. They, shall we say, add to the ambience and excitement. :)

The Jennifers Perform "And I'm Telling You (I'm Not Going)"

J-Hud and Fantasia perform "I'm His Only Woman"