Eight fire engines and around 60 firefighters were called to a fire at a restaurant with dwellings above on Pont Street in Belgravia.
Part of the basement of the building and a small part of the offices on the first floor were damaged by fire. All of the ducting (extraction system), from the basement to the roof level, was destroyed in the blaze. Six staff and seven diners left the building before the Brigade arrived.
Firefighters wearing breathing apparatus used fire escape hoods on one woman and one man, who were led to safety from the third floor of the building.
The cause of the fire is believed to have been caused by the ignition of oil and fat within the extractor hood and ducting.
A London Fire Brigade spokesperson said: "We'd like to remind hotel, restaurant and takeaway owners to ensure they don't have dirty ducting. If you don't clean the ducting in your extraction system regularly, you're at a greater risk of ducting fires.
"You should also make sure you keep the hob, cooker hood and extractor fan clean too – built up fat and grease can ignite and cause a fire."
The Brigade was called at 2240 and the fire was under control by 0209. Fire crews from Chelsea, Kensington, Soho and Lambeth, Euston, Chelsea and Fulham fire stations were at the scene.
Firefighters' top tips for restaurants and takeaways: