Four fire engines and around 25 firefighters were called to a fire at a flat on Rose Hill in Sutton.
Firefighters tackled a blaze in a flat above a detached shop where part of the ground floor shop and first floor flat were damaged by the fire.
The Brigade was called at 1117, the fire was under control by 1216. Fire crews from Sutton, Mitcham and Wimbledon fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.