Eight fire engines and around 60 firefighters were called to a fire at a warehouse on Morson Road in Enfield.
Two shipping containers and 14 vehicles were destroyed by the fire. There were no reports of any injuries.
Station Commander Dave Bracewell, who was at the scene, said: "Firefighters were faced with a well developed blaze on arrival.
"Crews worked hard to stop the fire spreading to surrounding buildings and a turntable ladder was used to tackle the blaze from height.
"The fire produced a significant amount of smoke, so residents in the area were advised to keep their doors and windows closed."
The Brigade's 999 Control Officers took 13 calls to the blaze.
The Brigade was called at 0130 and the fire was under control by 0342. Fire crews from Chingford, Enfield, Edmonton, Woodford, Tottenham and surrounding fire stations were at the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.