Four fire engines and around 25 firefighters were called to garages alight on Lorne Gardens in Croydon.
Two single storey garages were destroyed by the fire and part of another garage was damaged as well as a small amount of the sofits and facias of a nearby house. There were no reports of any injuries.
The Brigade's 999 Control Officers took six calls to the blaze.
The Brigade was called at 0539 and the fire was under control by 0633. Fire crews from Woodside, Beckenham and Croydon fire stations were at the scene.
The fire is believed to have been electrical.