A teenager was knocked out by a single punch to the face, police said as they released CCTV footage of the incident in a bid to catch his attacker.
The 19-year-old had to have a plate inserted in his jaw after he was attacked by a stranger in Guildford town centre in the early hours of 11 September last year.
Surrey Police said the victim was walking home from a night out when he was approached by three men he did not know.
One of the men can be seen punching the teenager in the face, who then crashes to the ground.
He suffered “grievous bodily harm injuries” and had to have surgery on his jaw, investigators said.
The three men then ran off leaving passers-by to run over and help the victim.
The are described as white, about 20 years old and about 6ft tall.
One of the men was wearing a black hoodie, jeans and white trainers, another was wearing a long-sleeved white T-shirt and black trousers, and the third a white T-shirt, jeans and a small shoulder bag.
"It highlights how just one punch can cause serious injury and have devastating consequences," said investigating officer PC Kieran Coffey. “The victim had to have a plate inserted in his jaw following the assault and we are really keen to bring his attackers to justice.
“He did not know any of these men and was walking home after a night out when the incident took place."
He added: “I am hoping that releasing the video footage will prompt someone into coming forward.”
Anyone with information should contact Surrey Police on 101 (999 in an emergency) quoting reference PR/45180097417.
You can also give information anonymously to the independent charity Crimestoppers on 0800 555 111.
