The Oscar-winning actress was seen sporting one heck of a tan and a spaghetti strap Dior dress which plunged at the back before she took it upon herself to whack the Harry Potter star - equally chic in a black one-shouldered number - in the face while posing for pictures.Scroll for pictures
LOVE COUTURE? See all the pictures from Dior's Autumn/Winter 2014/15 show in the gallery below...Fortunately for Jennifer (and everyone else in the room) Emma seemed to laugh the whole thing off as just another one of Jen's goofs.
As well as becoming well versed in the new art of the red carpet photo bomb, Jennifer was also pictured trying to pry Lupita Nyong'o's Best Support Actress award from her hands backstage at the Oscars this year.
MORE! What happened when Jennifer Lawrence took this joke too far... And paid the price for it?