A teenager who egged on a friend in a fight has been convicted of aiding and abetting grievous bodily harm.
The assault left the victim in a coma for more than a week. Surgeons had to remove parts of his skull to relieve pressure on his brain.
The incident took place at outdoor basketball courts off Rowlatts Hill Road, east Leicester, on September 18, 2014.
The 18-year-old victim willingly turned up to a pre-arranged fight with his attacker, Ryan Gallagher, 17, of Booth Close, Rowlatts Hill Estate, Leicester.
There were two confrontations moments apart which left the victim unconscious.
Ben Thomas Hayes, 17, of Balderstone Close, Rowlatts Hill Estate, Leicester, filmed both confrontations on his mobile phone. He recorded himself making encouraging comments to Gallagher.
Hayes has admitted aiding and abetting grievous bodily harm; today he was sentenced to an eight month detention and training order.
Gallagher admitted causing grievous bodily harm at an earlier stage. He was sentenced to four yearsâ€™ detention.
Detective Constable James Willoughby investigated the case. He said: â€œThis could easily have been a murder investigation. It left the victim with severe head injuries, and for many days his life was in the balance.
â€œThese convictions send out two clear messages. The first, if you are involved in a fight, the fact the other person was a willing participant will not save you from facing charges.
â€œThe second is that if you encourage someone to commit a crime, you share responsibility and can also face charges.â€
A number of other people were arrested during the investigation, but none was charged.
The sentencing judge lifted restrictions which would normally prevent juvenile defendants from being named.