And there was no-one prouder than her parents - who were cheering her on in the audience. Mum Sharon was reduced to tears by her daughter's performance, while dad Ozzy led the crowd in a standing ovation.
For her first dance in the competition, the 24-year-old, dressed in a purple and pink ball gown, performed a Viennese Waltz with partner Louis van Amstel.
And the moment the music stopped, the TV personality, who has lost a stone in training, ran over to kiss and embrace her parents, who were sat alongside her fiance Luke Worrall.
"Kelly, I cannot believe my eyes," judge Bruno Tonioli told the delighted blonde. "The wild child rock princess, transformed into a vision of grace and elegance in a world of impeccable style."
That sentiment was echoed by fellow judge Len Goodman who described Kelly's dance as "the best Viennese Waltz of the night".
As for the lady herself, she was clearly overwhelmed by the response.
The London-born star, who had said she wanted to make her dad proud before the show began, said backstage: "That was the most fun I've ever had in my life! I can't believe I'm crying!"