Firefighters were called out after a man decided to have a bonfire in the middle of the night.
When firefighters arrived it turned out a man was simply having a bonfire that had got out of control.
The crew used the man's own hose to put the fire out and advised him against holding such a large bonfire again.
A spokesman for Wallington fire station said: "It was slightly out of control.
"We advise people to make sure they keep their bonfires in those brazier bins you can buy, or to make sure they are no bigger than them.
"That way they do not tend to get out of control."
Sutton Council suggests it is seldom necessary to have a bonfire and encourages people to use its garden waste collection service instead.
It advises people only to burn dry material and never to burn household rubbish and to choose a day when the wind will disperse smoke quickly without blowing it into neighbours' gardens.