A Tesco Express in Penge was damaged by a fire last night.
The London Fire Brigade was called to Croydon Road just after 1am.
A spokeswoman said part of the supermarket's stock room was damaged by the fire.
Joanna Laboga, who lives next door, told News Shopper she was woken up after "suddenly feeling heat".
She added:" I thought that maybe my heater was turned on. Then I saw a big flame, maybe three to four metres.
"It was horrible. My window is right next door."
She immediately left the building and joined neighbours outside.
Ms Laboga has lived on Croydon Road since August - but last night's scare has encouraged her to maybe move somewhere else.
She said: "Sometimes I think this Tesco is very unlucky. There has been two to three robberies since I have been here and windows have been smashed."
The London Fire Brigade, who sent two fire engines, said the fire was under control by 2.08am.
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