Check out our edit below for plenty more party dresses, then style yours with court heels and a colour pop clutch a la Kelly.
The son of billionaire businessman and former KGB agent Alexander Lebedev, Evgeny is well-known as a playboy and has dated the likes of Geri Halliwell, Sophie Dahl and and actress Joely Richardson.
Her little green snakeskin box clutch gave the outfit a much-needed pop of colour, but it was Kelly's dress that really did all the work here.
It's by Gina Bacconi and the embellishment ensures it exudes old school Hollywood glamour.
The mother-of-one is said to have forged a close friendship with Russian billionaire Evgeny Lebedev and was spotted enjoying a cosy date with him in London last week.
Evgeny - who is 15 years Liz's junior - was spotted leaving a posh Central London home with the British star, but kept his distance as they climbed into a chauffeur-driven Bentley.