The Duchess was the epitome of sophistication in a black knee length dress by Alice Temperley as she arrived at SportsAid's annual ball in London.
She teamed the chic number with a red clutch bag and her £450 Jimmy Choo Cosmic suede black pumps. She wore her glossy brunette locks in loose waves.
She recycled the vibrant red Alexander McQueen clutch bag from a previous evening event for her former university St Andrews in 2012.
It isn't the first time she's teamed the statement clutch with a black Temperley gown.
The formidable fashionista worked a similarly sensational red carpet look at the War Horse premiere in London in January 2012.
The sporty 31-year-old will present the One-to-Watch Award which "honours a young British sportsman or woman who has demonstrated extraordinary commitment to their sport and career." Champion diver Tom Daley is a previous recipient of the award.
The glittering ball takes place at Supernova, a pop up venue in the capital's Embankment Gardens.
In April 2013 Kate became Patron of the charity, which provides financial support for promising young athletes. She attended one of the charity's workshops in London on her first official solo royal engagement after giving birth to baby George.