A Fire and Emergency New Zealand spokesman said the fire started in a diesel generator at a commercial property in Wilkie Rd.
Fire crews were called about 7.55am after nearby pine trees caught on fire, he said.
Two crews, from St Kilda and Dunedin Central, fought the blaze and a third from Lookout Point was called.
One lane of the Southern Motorway was blocked while crews fought the fire.
Police carried out traffic control, while fire crews dampened the area from the motorway side, the Fenz spokesman said.
The St Kilda crew was cooling down diesel and hydraulic oil from the generator.
The fire was out and crews had left the scene by 9.10am, the Fenz spokesman said.
Witnesses said an impressive plume of smoke rose from the fire.