About 60 firefighters battled a blaze at Countdown in West City Mall Henderson after being called just after 9.30pm.
A fire at a West Auckland supermarket is now out.
The fire was a third alarm, meaning crews from across Auckland were called.
A spokesperson for Fire and Emergency said it is unclear how much of the building was on fire.
Local business owners are being let back into neighbouring premises to check for damage.
Good Fortune Chinese Restaurant manager Ella Lin said her store is five metres away and after smelling smoke and hearing the alarms, had to close early.
Lin said she will wait until tomorrow to find out what the damage is.