British actress Carey Mulligan bagged the role of Daisy in Baz Luhrmann's The Great Gatsby by giving Leonardo DiCaprio a surprise kiss during her audition.

The Australian filmmaker recruited leading man DiCaprio to help pick an actress to play Jay Gatsby's love interest Daisy Buchanan in the film, and it was Mulligan's brave smooch that really impressed the actor.

"Leonardo was at every audition. He worked with me - it was work. He is not an acting snob but I guess if he was a chef, he can really tell what is fine cuisine," Luhrmann told The Hollywood Reporter.

He said they both knew instantly that Mulligan was their leading lady.

"So she does the scene, absolutely fantastic, and grabs him (DiCaprio) and kisses him. She went out the door and I was just thinking, 'My God, that is Daisy Buchanan.'

"I thought, 'I wonder what Di thinks' and he said 'The way Carey manifests Daisy is like something Gatsby would never have met in his life, something so delicate that he would want to protect her to an obsessive and almost impossible level.'

"And then it was done. It was done," Luhrmann recalled.

The Great Gatsby will have its world premiere in New York on May 1.

- WENN