The Letters To Juliet actress showed off her super-svelte figure at the star studded event in this off-white silk number that boasted a stunning v-shaped neckline with lashings of lace, and a flippy fishtail hem but she set tongues wagging as soon as she stepped to the side.
Amanda's dress featured a gaping hole where the sassy, floaty hemline joined the slip dress and it also looked like the bronde beauty had forgotten to lace up the corset-style back before leaving her apartment.
That said, we trust Amanda's fashion credentials and totally reckon the frock is supposed to be worn like that, however, this isn't the first time the Ted 2 star has drawn gasps!
Last month the stunner who lapped up the attention on the red carpet, made her debut at the Shiseido launch party in Tokyo but seemed to be wearing her frock, which consisted of an asymmetric hem and trailing buttons, back to front!
Of course, she managed to pull it off.
Even though her dress may have divided opinion, Amanda's make-up was a surefire win.
Ms. Seyfried made like Little Mix's Perrie Edwards with lashings of smokey brown eyeliner and wore her lustrous lengths slicked back into a chic chignon bun with a deep side parting.
A dab of clear gloss and a pair of sparkling statement earrings was all she needed to complete her unusual yet eye-popping look.
Amanda schmoozed with the likes of Zendaya and model Karlie Kloss at the glitzy event in the Big Apple.
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!