Five fire engines and 35 firefighters were called to a fire at a block of flats on Frances Street in Woolwich.
Half of a four roomed flat on the ground floor was damaged by fire.
One woman left the property before the Brigade arrived and was treated at the scene for smoke inhalation by London Ambulance Service.
The Brigade was called at 1008 and the fire was under control by 1046. Fire crews from East Greenwich, Plumstead, Eltham and Greenwich fire stations were at the scene.
The cause of the fire is under investigation.