Four fire engines and around 25 firefighters were called to a flat fire on Tabard Street in Southwark.
Part of a three-roomed flat on the third floor of the building was damaged by fire. One man left the building before the Brigade arrived.
The Brigade was called at 1205 and the fire was under control by 1257. Fire crews from Old Kent Road, Dockhead, Lambeth and Shoreditch fire stations attended the scene.
The cause of the fire is believed to have involved a lighter that was being refilled.