Firefighters were called to the blaze at Bentley’s Barbers on Manukau Rd at 2.44am.
Fire and Emergency northern shift manager Josh Pennefather said the block of shops measured around 40m by 20m, with residential property in the storey above.
However, the fire remained small and was contained to one shop. Four fire trucks were sent to the scene and the blaze was extinguished within half an hour.
A Herald photographer said multiple ambulances attended the scene - however Pennefather said everyone was out of the building and there were no injuries.
The fire is considered suspicious, and police are on scene, along with two fire investigators. One fire truck is still attending, with firefighters monitoring hotspots.
A police spokesperson said a scene examination will take place today.
The spokesperson said police are urging anyone with footage or information that may help their investigation to call them on 105 referencing file number 240731/8638.