Four fire engines and around 25 firefighters were called to grass alight on Howbury Lane in Slade Green.
Around two hectares of grass was alight in a recreation ground. There were no reports of any injuries.
A London Fire Brigade spokesperson said: “The warmer weather we have been having makes the ground extremely dry, which unfortunately means grassland and parks will burn quickly when exposed to even the smallest of sparks.
“If you see a grass fire, don't attempt to put it out yourself as grass fires can travel very quickly and change direction without warning. Call the Brigade and let us know where the fire is.”
The Brigade's 999 Control Officers took 18 calls to the blaze.
The Brigade was called at 1444 and the fire was under control by 1531. Fire crews from Bexley and Plumstead fire stations were at the scene as well as colleagues from Kent Fire and Rescue Service.
Brigade’s top tips on grass fires: