Four fire engines and around 25 firefighters were called to a fire at a fast food restaurant on Twin Tumps Way in Thamesmead.
Part of the round floor of a detached drive-through was damaged by fire. There were no reports of any injuries.
The Brigade was called at 0037 and the fire was under control by 0241. Fire crews from Plumstead, Erith and East Greenwich fire stations attended the scene.
The cause of the fire is under investigation.