Four fire engines and around 25 firefighters were called to a fire at a distribution warehouse in Church Manorway, Erith.
A conveyor belt and external motor were damaged by fire. One sprinkler head actuated and helped to suppress the fire.
A London Fire Brigade spokesperson said: “This incident highlights the clear benefits of sprinklers to businesses and we would urge all companies and business owners to install them.
“As well as limiting fire damage and being potentially life saving devices, sprinklers and other fire suppression systems help with business continuity by minimising disruption and allowing businesses to get back to normal as soon as possible.”
The Brigade was called at 1909 and the fire was under control at 2212. Fire crews from Erith, Bexley and Plumstead fire stations attended the scene.
The cause of the fire is under investigation.