Four fire engines and around 25 firefighters were called to a fire at a café with flats above on Church Road, Barnes.
Neighbours saw smoke coming out of the café and called 999. The flats above were empty at the time of the fire.
Watch Manager Luke Rowson, who was at the scene, said: “We believe the fire was caused by candles left unattended on a mantelpiece.
"It's lucky that no one was injured on this occasion, but this incident is a timely reminder about the importance of taking care when using candles.
“It’s really important you never leave them unattended and keep them away from curtains and anything else which can easily catch fire.”
A small part of the ground floor cafe was damaged by fire. Six people left adjacent properties before the arrival of the Brigade.
The Brigade was called at 0119 and the fire was under control at 0250. Fire crews from Hammersmith, Wandsworth, Fulham fire stations attended the scene.