Four fire engines and around 25 firefighters attended a fire at a flat on Grayswood Gardens in Raynes Park.
Part of a ground floor flat was damaged by fire. One man left the flat before firefighters arrived and was left in the care of the London Ambulance Service.
The Brigade received the first of four calls about the incident at 1539 and mobilised crews from New Malden, Wimbledon and Sutton fire stations to the scene. The fire was extinguished by 1636.
The cause of the fire is under investigation by the Brigade and Metropolitan Police.