Four fire engines and around 25 firefighters were called to a fire at a flat in Richmond Road in Thornton Heath.
Half of a three-roomed flat on the first floor of a mid-terraced house converted into flats was damaged by the fire. Two people left the property before the Brigade arrived. There were no reports of any injuries.
The Brigade was called at 0759 and the fire was under control at 0903. Fire crews from Norbury and Croydon fire stations attended the scene.
The cause of the fire is under investigation.