Margot Robbie's shocking act on Leonardo DiCaprio which secured Wolf of Wall Street role

From her humble beginnings on the set of Australian soap Neighbours, soon rocketed to the heights of Hollywood stardom, a journey marked by a bold choice during her audition for The Wolf Of Wall Street.

At just 26, the actress left director Martin Scorsese and actor Leonardo DiCaprio speechless when she took a daring departure from the script of the black comedy film.

Writing for Time Magazine's 100 Most Influential People issue in 2017, Scorses recalled how Robbie, now 34, secured her role by delivering a staggering, unscripted slap to DiCaprio's face.

Describing the unforgettable moment, Scorsese recounted: "She clinched her part in The Wolf of Wall Street during our first meeting-by hauling off and giving Leonardo DiCaprio a thunderclap of a slap on the face.

"[It was] an improvisation that stunned us all."

This was the first time Scorsese had publicly described Robbie's audacious approach, although she herself expressed fears about potential legal consequences following her unrehearsed action.

Speaking to Harper's Bazaar in 2015, Robbie delved into her thoughts about the career-defining moment.

"In my head I was like, 'You have literally 30 seconds left in this room and if you don't do something impressive, nothing will ever come of it. It's a once-in-a-lifetime chance, just take it.' And so I start screaming at him and he's yelling back at me. And he's really scary. I can barely keep up," she recalled.

"And he ends it saying, 'You should be happy to have a husband like me. Now get over here and kiss me.' So I walk up really close to his face and then I'm like, 'Maybe I should kiss him. When else am I ever going to get a chance to kiss Leo DiCaprio, ever?'"

However, Robbie decided to go completely off-script and chose to do something that DiCaprio, who turns 50 today (November 11), would never forget.

The Suicide Squad star continued: "But another part of my brain clicks and I just go, Whack! I hit him in the face. And then I scream, 'F**k you!' And that's not in the script at all. The room just went dead silent and I froze."

To her surprise, both DiCaprio and Scorsese burst out laughing, with the Oscar-winning actor even asking her to hit him again. A week later, Margot discovered she would be portraying Naomi Lapaglia, the role that completely changed her life.