Carling Poynter, 18, stabbed a 15-year-old during an altercation in Burdock Close, Crawley, at around 11.20pm on May 5.
The boy was taken to hospital in a serious condition and has since been discharged.
Poynter, of Snowdrop Close in Crawley, was arrested on May 6 on suspicion of attempted murder and possession of a knife and was later charged.
A 17-year-old boy and a 35-year-old woman were also arrested on suspicion of assisting an offender at the same time. Both have since been released with no further action taken.
READ MORE: Teenager, 15, in serious condition after being stabbed – man arrested
The 15-year-old boy was taken to hospital in a serious condition (Image: Sussex News and Pictures) Poynter was found guilty of grievous bodily harm following a nine day trial at Lewes Crown Court on November 7.
He is due to be sentenced on January 9.
Detective Superintendent Suzanne Joseph, of the major crime unit, said: “This was an incident which caused a lot of concern in the community, as well as a lot of trauma for the victim’s family.
“Poynter’s actions impacted a lot of people around him and justice has now been served for this appalling crime.
“This was an altercation which got out of hand.
“Poynter is a dangerous individual who caused serious harm to the victim.”
