Four fire engines and 21 firefighters and officers were called to a fire at a house converted into flats in Hartfield Road in Wimbledon this morning.
Half of a flat on the first floor was damaged by fire.
Two people left the property before the arrival of the Brigade and were treated for smoke inhalation at the scene by London Ambulance Service.
The Brigade was called at 0620 and the fire was under control at 0756. Fire crews from Wimbledon, Mitcham, Tooting and New Malden fire stations attended the scene.
The cause of the fire is under investigation.