Four fire engines and around 25 firefighters tackled a fire at a mid terrace house on Chilthorne Close in Forest Hill.
A flat on the ground floor was destroyed by the fire. One person left the building before the Brigade arrived. There were no reports of any injuries.
Control Officers took the first of six calls at 1213 and mobilised crews from Forest Hill, Greenwich, Lee Green and New Cross fire stations to the scene. The incident was over for firefighters at 1330.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.