Firecrews were called to put out a fire caused by unattended cooking.
They were called to the blaze yesterday just after 4.45pm in Burke House, Hope Street, Battersea.
Two fire engines from Battersea and a third from Chelsea attended the scene.
It was put out within minutes, while the person in the flat evacuated the property before crews arrived.
A small part of the flat was damaged by smoke and firefighters stayed at the scene to install smoke alarms.
A spokesperson for the fire brigade said there have been a recent spate of fires caused by unattended cooking and warned people to take more care.