Ten fire engines and around 70 firefighters were called to a fire at a shop with flats above on High Road in Wood Green.
Part of the roof and the basement of the building were damaged by fire. The entire extraction system from the basement level to the roof was also destroyed by the blaze. There were no reports of any injuries.
Station Commander Nathan Hobson, who was at the scene, said: "The fire had travelled via the extraction system to the roof of the building and crews worked swiftly to bring the fire under control.
"Thankfully, smoke alarms fitted inside the property were able to give the earliest possible warning to the fire and alerted the shop owner who then raised the alarm and made the first of nine calls to the Brigade. Seven people left the building before the Brigade arrived.
"High Road was closed whilst crews worked to make the scene safe and we urged people to avoid the area.
"There was smoke in the area and local residents were encouraged to keep their windows and doors closed."
The Brigade was called at 1804 and the fire was under control by 2039. Fire crews from Tottenham, Hornsey, Southgate, Edmonton and surrounding fire stations attended the scene.
The cause of the fire is under investigation.