Four fire engines and 21 firefighters and officers were called to a fire at a block of flats in Halifax Road, Enfield.
Most of a four-roomed flat on the ground floor was damaged by the fire.
Seven people were evacuated from neighbouring flats by the Brigade and there were no reports of any injuries.
The Brigade was called at 0348 and the fire was under control at 0458. Fire crews from Enfield and Edmonton fire stations attended.
The cause of the fire is under investigation.