A second man, also aged 21, was also found with stab wounds after the incident in Ascalon Street, police said.

They were both taken to hospital for treatment and have since been discharged, police said.

Detectives said the two victims were driving in a beige Fiat 500 on Wandsworth Road when they were involved in a “verbal altercation” with the occupants of another car following a minor collision.

The pair were chased at high speed by the men in the other car, which is described as a black hatchback with blacked-out windows, before getting out of the car on Ascalon Street and being attacked.

The suspects drove off after the incident, officers said.

Detective Constable Simon Monga, from Wandsworth CID, said: “This was a violent and unnecessary attack. A minor traffic collision has resulted in two men being stabbed. It is only by sheer luck that their injuries are not more serious.”

Police have released an image of the vehicle they want to locate and are appealing for anyone who saw either the beige Fiat 500 or black hatchback on Wandsworth Road and in the Patmore Estate at around 8.45pm on March 8 to contact them.

The driver of the suspects’ vehicle is described as white or mixed race, aged in his early to mid-20s, 6ft tall, of large build and with a shaved head and stubble. He was wearing a navy blue tracksuit.

His passengers were all young black men, police said.

Mr Monga added: “If you have any information about the stabbing and the identity of the suspects, please call police without delay. It is vitally important that we trace these people.”

Anyone with information can contact Wandsworth CID on 0203 276 2603 or 101 quoting ref: 7495/8March.