Firefighters were called to an address on Worcester St, near Fitzgerald Ave, just after 6am on Thursday.
Fire and Emergency shift manager Andrew Norris said when crews arrived the flat was "well-involved" in flames.
He said the blaze is being treated as suspicious and a fire investigator will be at the scene this morning.
Two crews remained at the property this morning to dampen down hotspots but the fire was contained by about 9.30am.
-By Courtney Winter