The A23 was closed to traffic coming into Brighton after fire crews were called to tackle a house which was ablaze a few hundred yards from Preston Circus Fire Station.
Traffic was diverted away from Beaconsfield Road which carries southbound traffic into Brighton as firefighters tackled the blaze in a property between Stanford Avenue and Springfield Road.
East Sussex Fire and Rescue Service were called out at about 3.45pm and had put out the fire by about 6pm.
The A23 remained closed between Stanford Avenue and Preston Circus while firefighters were damping down and checking for hotspots.
There were queues of traffic and delays across the area.
The fire service said: “East Sussex Fire and Rescue Service attended a fire at a property in Beaconsfield Road, Brighton.
“Two appliances initially attended at 3.46pm and this was escalated to a third appliance at 3.53pm from Brighton and Hove.
“Additionally, an aerial ladder platform attended the incident.
“Crews wearing breathing apparatus used one hose-reel jet to tackle the fire.
“There are no reports of any casualties.
“The incident has now been scaled back to one appliance and crews are expected to remain at the scene for a while.
“The cause is under investigation.”