Four fire engines and around 25 firefighters tackled a house fire on Durnsford Road in Wimbledon Park.
Part of the ground floor of a mid-terraced house was damaged by fire. There were no reports of any injuries.
The Brigade was called at 0639 and the fire was under control by 0750. Fire crews from Wimbledon, Wandsworth, Tooting and Mitcham fire stations attended the scene.
The fire is believed to have been accidental and caused by a downlight.