The fresh-faced beauty, who dyed her platinum locks raven black at the end of last year, started to wobble as she sashayed down the runway in a pair of impossibly high Burberry platform heels.
She fell to her knees, then after getting up and soldiering on, keeled over again. So she promptly removed the troublesome shoes and completed her turn barefoot – smiling and giggling all the while.
Fittingly, Agyness was taking part in the Fashion For Relief Haiti benefit organised by Naomi Campbell – who herself ended up on her derriere during a Vivienne Westwood show in 1993.
Naomi had roped in a bunch of her famous friends – including Kelly Osbourne, Helena Christensen and the Duchess of York – to model a selection of the gowns donated by over 140 different of designers.
The creations will be auctioned on net-a-porter.com in march to raise funds to help earthquake victims in Haiti.
And the spotlight fell on late designer Alexander McQueen, when a group of seven designs from his final collection, Plato’s Atlantis, were featured in the show.
Sarah Ferguson, who opened the presentation, said a few words about the tragic loss. “I know this has been a very sad week,” she told audience members, who had each paid $150 a ticket.
"This is for him tonight. I know Naomi is very grateful you are all here. All I can say is - to Alexander McQueen, thank you, thank you.”