The first lady was a vision in blue last night, wearing a stunning one-shoulder gown by one

of Rent the Runway's faves, Peter Soronen. 

As is Peter Soronen's signature, the gown features a corset top with a lace-up back. The concept of the gown, one-shoulder aside, recalls the lavender Peter Soronen gown the first lady wore for the Kennedy Center Honors in December.

In an interview, Peter Soronen said: "I love the structured bodice that I do for her. I put it in a lot of my dresses. I drape, pin and stitch all that lightweight chiffon -- this look works well on the first lady.” We couldn’t agree more – she looks amazing! -- Derek