Yarnold outstripped Germany’s Jacqueline Loelling by 0.45sec after a blistering final run of 51.46sec, celebrating wildly when the last runner, Austria’s Janine Flock, finished out of the medals.
Britain’s Dom Parsons took bronze in the men’s event a day earlier.
Rival teams had questioned the legality of Britain’s innovative, drag-reducing skinsuits, but Olympic officials said they had been checked and cleared for use.
