January Jones' Sexy YSL Look

Looking straight off the set of a '40s film noir rather than the '60s set of Mad Men, January Jones was suitably glam for the Metropolitan Opera premiere of Manon.

January's YSL gown looked slightly basic from the front but from the side revealed a sexy slit and from the back, a stunning cut-out.

Her jewels were Cartier, and black peep-toes, and a clutch - also YSL - completed the look.

Pics from Zimbio and PacificCoastNews