Six fire engines and around 40 firefighters were called to a house fire on Hayes Way in Beckenham.
Part of the ground floor and a small part of the first floor of a detached house were damaged by the fire. There were no reports of any injuries.
Station Commander Daniel Capon, who was at the scene, said: "Fortunately no one was at home at the time of the fire, but neighbours heard smoke alarms inside going off and called 999.
"This incident is another reminder about the importance of having smoke alarms fitted in your home. You should have working smoke alarms in every room where a fire can start, plus a heat alarm in the kitchen and the bathroom. They should be tested regularly.
"As this incident shows, even if you're not at home when a fire breaks out, smoke alarms can make other people aware.
"Crews worked hard to contain the fire as much as possible.
"Firefighters wearing breathing apparatus rescued a dog from the ground floor of the property which was taken to the vets to be checked."
The Brigade was called at 1046 and the fire was under control by 1322. Fire crews from Bromley, Addington, West Norwood and Forest Hill fire stations were at the scene.
The fire is believed to have been accidental and electrical.