Firefighters were called to a road traffic collision on Ham Gate Avenue in Ham.
A car collided with a gate. One woman was trapped and released from the vehicle and one man left the vehicle before the Brigade arrived. They were taken to hospital by London Ambulance Service crews.
A London Fire Brigade spokesperson said: "We don't want to have to cut you from the wreckage of a car, and we don't want you to have to live with the knowledge that you could have prevented a crash that saw someone else lose their life.
"Familiarise yourself with our road safety advice and stay safe.
How to stay safe on your journey
The Brigade was called at 0149 and the incident was over for firefighters by 0223. Two fire engines and a fire rescue unit from Kingston, Richmond and Heston fire stations attended the scene.