The actress was jaw-dropping in a pillar box-red Stella McCartney column gown, which featured two top-to-toe lace panels, a sweetheart neckline and a low-back bodice.
Throw in a no-fuss updo, intricate drop earrings, a flawless complexion, et voila! Hard-to-beat near-perfection.
Stella actually won the magazine shindig's Best International Designer award, and who better to present it to her than the McCartney-clad Kate herself?
Both ladies were the big winners of the night.
See all the pics from the bash right here: