Four fire engines and around 25 firefighters tackled a fire at a semi-detached house converted into flats on Edencourt Road in Tooting.
Part of a ground floor flat was damaged by fire. There were no reports of any injuries.
The Brigade was called at 2216 and the fire was extinguished by 2312. Crews from Bromley, Mitcham and Norbury fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and Metropolitan Police.