Wendi Deng gained popularity for springing to her husband's aid when a protester threw a custard pie at him as he appeared before MPs to answer questions about phone hacking in 2011.
At 44, Ms Deng is 38 years younger than Mr Murdoch, who is 82.
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Joshua beat the older, more experienced boxer in front of 90,000 fans in Wembley Stadium.
Dry for most of the night. Rain in the southwest by dawn.
Host Paddy McGuinness tweeted a tribute to contestant Charlie Watkins whose date was featured in Saturday's episode.