Sienna Miller hosted the grand opening of Esquire House LA this weekend.
The British actress does a complete 180 by going from looking ridiculous in an oversized Matthew Williamson gown, to divine wearing a Nina Ricci Fall 2010 dress.
The strapless elegant tiered dress with a peplum at the waist had touches of lace with the hem falling just below the knee.
Grey Stella McCartney pumps and sleek straight shiny blonde hair completed her look.
Credit: Style.com & Getty