(LONDON) -- Naomi Watts shone in a white Versace dress as she walked the red carpet at the world premiere of her biopic Diana at the Odeon Leicester Square in London Thursday evening.
The Oscar nominee's dress, which featured a cleavage-baring keyhole opening and a long slit showing off her left leg, was created by the Italian fashion house that was the real Princess Diana's favorite.
The actress was joined by her co-stars, including Naveen Andrews, who plays Dr. Hasnat Khan, the Pakistani physician with whom the late Princess of Wales was said to have been deeply in love with in the years before her death on Aug. 31, 1997.
Watts, who initially turned down the role but found she couldn't stay away, told the Daily Mail she was nervous about whether or not Diana's sons Princes Harry and William would see the film. The actress said if they do, she hopes they "feel we've been respectful and upheld her memory."
On the red carpet, Watts explained she didn't go about portraying Diana in the usual way.
"I did it in the reverse direction. Starting with the look and the voice, obviously being the most important one and then getting into the interior life after," she said.
Diana is set to open in the U.S. on Nov. 1.
Copyright 2013 ABC News Radio