Two fire engines and 10 firefighters were called to a fire at a flat in Lawrie Park Gardens in Sydenham.
The kitchen of the second floor property was gutted by the fire. One man was rescued by firefighters wearing breathing apparatus and he was treated at the scene by London Ambulance Service crews.
The Brigade was called at 0038 and the fire was under control at 0124. Fire crews from Beckenham and Forest Hill fire stations attended the scene.
The cause of the fire is under investigation.