The 42-year-old third Mrs Murdoch, who came from middle-class China to marry one of the world's most powerful media moguls, gave a dramatic stand-by-your-man display.
The Yale University business school graduate, yoga devotee and former News Corp employee reacted faster than anyone else seated around Murdoch, including his son James, when the tense questioning by a British parliamentary panel was interrupted by a man throwing a shaving-cream pie at her 80-year-old husband.
She sprang from her seat behind her husband to smack the assailant, in a scene witnessed by millions around the world watching television coverage on Tuesday of the latest developments in the News of the World telephone hacking scandal.
In doing so, Deng made the embattled News Corp chief look vulnerable, and herself strong. But the incident and her reaction also helped to take some of the heat off of Murdoch who had looked tired, disconnected and irritable earlier in the hearing.
"That's our Wendi," said Vanity Fair writer Michael Wolff, author of a Murdoch biography.