Reese Witherspoon Beams Alongside Cameron Diaz on First Night Out Post-Baby

Reese Witherspoon and Cameron Diaz attend the rag & bone Flagship store on October 26, 2012 in Los Angeles, California.  Donato Sardella/WireImage

Reese is ready to party!

Reese Witherspoon has been out and about in the daylight hours — running errands, cheering on son Deacon's soccer game — since welcoming son Tennessee James Sept. 27.

But the evening of Friday Oct. 26 marked the Devil's Knot star's first official night out since becoming a mom for the third time. Clad in a blue shift dress and ankle booties, the 37-year-old was among the bevy of A-listers on hand for the opening of Rag and Bone's new flagship store in Los Angeles.

Sans husband Jim Toth, Witherspoon had a gal pal to lean on: Cameron Diaz, wearing head-to-toe Rag and Bone, with her hair pooled back into a messy ponytail.

Witherspoon and Diaz — both pals to Rag and Bone designers David Neville and Marcus Wainwright, not to mention Gwyneth Paltrow and Chelsea Handler — were all smiles as they sipped champagne and caught up at the bash.

Other star at the bash include Emma Roberts and boyfriend Evan Peters (American Horror Story: Asylum), Mad Men's Kiernan Shipka, Mandy Moore, Vogue's Anna Wintour and daughter Bee Schaffer, Brittany Snow and Aziz Ansari.

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