Four fire engines and around 25 firefighters were called to a fire at a house on Mortlock Close in Peckham.
Most of the first floor of the terraced house was damaged by the fire and the second floor and staircase were destroyed.
One woman left the building before the brigade arrived. Crews wearing breathing apparatus rescued a man from the first floor of the property. The man and woman were both treated on scene and taken to hospital by London Ambulance Service crews.
The Brigade was called at 0609 and the fire was under control by 0837. Fire crews from New Cross, Peckham, Old Kent Road and Brixton fire stations attended.
The cause of the fire is under investigation.