Four fire engines and around 25 firefighters tackled a flat fire on Kidderminster Road in Croydon.
Part of a second-floor flat above a shop was damaged by fire. There were no reports of any injuries.
The Brigade was called at 1503 and the fire was under control by 1557. Fire crews from Norbury, Wallington and Mitcham fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.