And she even told off Big Brother's Aisleyne Horgan-Wallace for showing too much CLEAVAGE.
Mary was a surprise guest at last night's bash - but judging by what she encountered, we're not sure she'll return in the future.
The 81-year-old, a national treasure thanks to Bake Off, was surrounded by scantily-clad stars of more low-rent shows - some of whom suffered wardrobe malfunctions.
According to The Sun, Mary was less than impressed with the spectacle. When one person complimented her dress, she allegedly responded: "Someone had to bring a bit of class to the proceedings."
A source said: "Mary was the standout star compared to the likes of Chloe Khan, Laura Carter and Zara Holland, who are known for having sex on TV."
"She made a conscious effort throughout the night to keep her distance from the wannabes and was shocked by their risqué outfits."
The mole added that Mary offered some choice words to Aisleyne - whose outfit left nothing to the imagination - saying: "She was shocked by the amount of cleavage Aisleyne had on show and even told her to keep her top closed."
Aisleyne has Tweeted a photo of herself with Mary, and claimed she'd 'kept her promise'.
Mary faced further embarrassment when she did a backstage interview with ceremony sponsor Hayu on a Facebook Live stream.
During the chat, she admitted having no idea who the Kardashians are - only for the presenter to hold up pictures of the sisters' rears and ask who she thought has the "soggiest bottom".
"Why would you ask her this line of questioning?" commented one viewer, while another reckoned: "She's desperate to leave."
It wasn't all a downer for Mary, as she did take home an award for Best Television Chef. She exclaimed: "I’m thrilled to bits!"