Julia Fox joins Madonna on stage during the Celebration tour after revealing she auditioned for her biopic

On the final date of a six-date residency at The O2 Arena in London, as part of the Ballroom Interlude where her dancers have a vogueing competition, Madonna invited the it-girl on stage as one of the judges.

Earlier in the week, Madonna invited FKA twigs up on stage for the same segment, which saw Madonna's daughter Estere participate in a vogueing routing, with fans calling for a collaboration between herself and Beyoncé's daughter Blue Ivy who performed across a few dates on the Renaissance tour.

The career-spanning show included other highlights such as Madonna performing "Nothing Really Matters" for the first time since 1999 – and only the second time ever – as well as a new live version of "Live to Tell" dedicated to lives lost lives to AIDS, including her best friend Martin Burgoyne who was pictured behind her on the stage.

@fangirl11011 life doesnt feel real right mow. MADONNA and JULIA FOX!!! #madonna #madonnalondon #juliafox #juliafoxlondon #juliafoxmadonna #madonnajuliafox ♬ Vogue (Edit) - Madonna

Julia Fox recently discussed her audition for Madonna’s biopic, which has since been shelved so that she can concentrate on the Celebration tour.

In an appearance on Watch What Happens Live with Andy Cohen on Sunday (15 October), Fox recalled the first time she met Madonna and remembered having dinner in New York, at the Carbone restaurant, with "some really fabulous gays" a few years ago.

Speaking of their initial meeting, Fox said: “There’s so much strength in her vulnerability. When you meet her, she just has that ‘It’ factor. It totally makes sense why she is Madonna...Then we kind of kept in touch and she was doing her biopic and I really wanted to play Debi [Mazar],” Fox added, in reference to Madonna's lifelong friend and star of Goodfellas. “I went to her house and I read for her, and it was just all very surreal.”

Last year, Mazar discussed the potential of Fox being cast as her, noting: “Funny enough, she reminds me more of Madonna when we were young, than of myself...I’d obviously be flattered.”