Four fire engines and around 20 firefighters and officers were called to a fire at a house in Red Barracks Road, Woolwich.
Around half of the first floor of a mid terraced house was damaged by fire.
Two people left the property before the arrival of the Brigade and were treated at the scene for smoke inhalation by London Ambulance Service crews.
The Brigade was called at 0715 and the fire was under control at 0829. Fire crews from Plumstead and East Greenwich fire stations attended the scene.
The cause of the fire is under investigation.