Four fire engines and around 25 firefighters tackled a fire on Gipsy Road in West Norwood.
Part of a three roomed flat on the ground floor was damaged by the fire. One man was rescued from the building by firefighters and taken to hospital by London Ambulance Service.
Control Officers took the first of three calls at 2116 and mobilised crews from Norbury, Brixton and Tooting fire stations to the scene. The incident was over for firefighters at 2217.
The cause of the fire is under investigation.