Four fire engines and around 25 firefighters were called to a flat fire on Rotherhithe Street in Rotherhithe.
Half of a four-roomed flat on the ground floor of a residential block of flats was damaged by fire. One man was treated on scene by London Ambulance Service crews.
The Brigade’s 999 Control Officers took seven calls to the blaze.
The Brigade was called at 0742 and the fire was under control by 0843. Fire crews from Deptford, Dockhead, Old Kent Road and Dowgate fire stations attended the scene.
The cause of the fire has been recorded as undetermined.