Monday wasn't a bad day in Carey Mulligan's world -- while walking the red carpet at the Council of Fashion Designers of America awards, she got word that she had nabbed a lead role in Baz Luhrmann's upcoming adaptation of "The Great Gatsby."

The indie-film pixie burst into tears on the red carpet, according to Deadline, in front of Vogue Editor Anna Wintour and designer Karl Lagerfeld (Mulligan was wearing Chanel). 

"I was thrilled to pick up the phone an hour ago to the young Oscar-nominated British actress Carey Mulligan and say to her -- 'Hello, Daisy Buchanan,' " the "Moulin Rouge!" director said in an e-mail to Deadline.

Daisy is the doomed princess of the Long Island Sound in "Gatsby," for which Mulligan beat out serious rumored competition -- such as Blake Lively (who also attended the CFDA Awards -- awkward) and "The Town" starRebecca Hall.

Leonardo DiCaprio is set to play lead Jay Gatsby, with Tobey Maguire lined up as Gatsby's confidant Nick Carraway. One prior adaptation of F. Scott Fitzgerald's book was made byJack Clayton in 1974. Mia Farrow originated the role that now belongs to Mulligan, while Robert Redford broke in DiCaprio's shoes.