Four fire engines and around 25 firefighters were called to a shop fire on Parchmore Road in Thornton Heath.
Part of the ground floor of a mid-terraced shop with flats above was damaged by fire. Firefighters assisted a man to safety from a flat on the first floor. One man was taken to hospital by London Ambulance Service crews.
The fire is believed to have been accidental and caused by a tea light candle igniting a spilled flammable liquid.
A London Fire Brigade spokesperson said: "Candles, incense sticks and oil burners are one of the most common causes of fire. We’d recommend swapping traditional candles for safer flameless LED alternatives, but if you do use real candles, it’s so important to never leave them unattended.
“Always make sure that they’re held firmly in heat-resistant holders and placed on a stable surface where they won’t be knocked over.”
The Brigade was called at 1627 and the fire was under control by 1743. Fire crews from Norbury, West Norwood and Woodside fire stations attended the scene.