Sharon Stone looked back at the film that defined a major milestone in her career — and the actor who pushed her to her limits.

In a recent interview with Business Insider, the Hollywood star revealed how Robert De Niro challenged her during the filming of Martin Scorsese’s 1995 classic Casino. Stone played Ginger McKenna opposite De Niro’s Sam “Ace” Rothstein, and one heated argument scene between their characters turned into something very real for her.

“There’s a scene where we’re across a table arguing, and he says to me, ‘You’re a good actress, you know that?’” Stone recalled. “I remember how furious it made me because it was my dream to do it, and then he challenged me at the table. I thought, ‘Oh, you crossed a line today, mister.’”

Stone admitted she had auditioned for several roles in De Niro’s films before finally landing Casino, even telling her coach it was her career goal to one day “work with De Niro and hold my own.” That table scene, she said, became the moment she proved it to herself.

Despite the tension, Stone acknowledged it was exactly what the film needed. “He knew every button to go for with me because he is the greatest observational actor. He can crawl under your skin and get in there,” she said.

The performance earned Stone her first Academy Award nomination for Best Actress, along with nods from BAFTA and SAG. She ultimately took home the Golden Globe for Best Actress in a Motion Picture, cementing her place in Hollywood history.