Eight fire engines and around 60 firefighters tackled a fire at a motorcycle shop on Camberwell Road in Walworth.
At the height of the fire, the ground floor of the shop was alight. Firefighters evacuated around 30 people from two properties as a precaution. There are currently no reports of any injuries.
Camberwell Road remains closed between Grosvenor Terrace and Bethwin Road, so the public are urged to continue to avoid the area at this time.
One of the Brigade's 32-metre turntable ladders was used at the scene to help fight the fire from above.
The Brigade's Drone Team also attended the scene and provided the Incident Commander with an aerial view of the fire.
Control Officers took the first of 28 calls at 0438 and mobilised crews from Peckham, Old Kent Road, Brixton and surrounding fire stations to the scene. The fire was under control by 0709.
The cause of the fire is under investigation.