Six fire engines and around 40 firefighters responded to a fire in a restaurant on St James's Road in Croydon.
The basement space in a terraced building of three floors was partly damaged by fire. There are no reports of any injuries.
The Brigade was first called about the fire at 1940, and crews had it under control by 2210. Firefighters from Croydon, Norbury, Mitcham and surrounding fire stations attended the scene.
The fire is believed to have been accidental, starting in an electrical intake.