Violence erupted at a village funfair when a drunken teenager attacked two people with a bottle, causing head injuries.
A 19-year-old collapsed and was taken to hospital after having a vodka bottle smashed on his head. His injuries included a cut needing 10 stitches.
Christopher Cunningham-Pithouse (18), who carried out the attack at the funfair in Quorn, near Loughborough, had moments earlier struck another teenager who was on the ground.
He hit the youth, who was being attacked by someone else, on the head with the same bottle. The blow caused a cut needing three stitches.
At Leicester Crown Court, Cunningham-Pithouse, of Patrick Kelly Close, Alford, in Lincolnshire, admitted unlawful wounding and causing actual bodily harm on September 7. He was sentenced to 16 months detention.
Co-accused, Laura Connolly (18), of John Earl Road, Barrow upon Soar, admitted causing an affray.
She was said to have shouted threats while wielding another vodka bottle.
She was given a one-year community order with 100 hours of unpaid work.
Philip Gibbs, prosecuting, said: "The annual funfair was supposed to be a happy event, but on this occasion it turned ugly."
He said the defendants were with a group of friends, one of whom started brawling with someone from another group – which triggered a series of violent incidents.
Having been passed a 1.5 litre vodka bottle, Connolly threatened to "hit anyone who came near her" with it, said Mr Gibbs.
He said that when a young woman on crutches shouted to the scuffling youths to stop, Connelly raised the bottle in her direction, but no physical contract was made.
Sentencing, Judge Simon Hammond said Cunningham-Pithouse had an "atrocious criminal record" which included four assaults, attempted robbery and arson.
He said he accepted Cunningham-Pithouse did not start the violence.
However, the defendant joined in after drinking and having taken "a drug".
He said he was prepared to give Connolly a chance, as she was now in employment and determined to make "some-thing of her life".
Judge Hammond said: "Bottles can cause very grave injuries and can blind people." Daniel Bishop, mitigating for Cunningham-Pithouse, said: "The vodka bottle was taken there as a drink, not as a weapon.
"It was in his hand when the violence started and he used it in the way described.
"He had been out of trouble for 11 months before this incident, which has set him back."
Jane Hinds, for Connelly, who has no previous convictions, said: "She accepts she used aggressive language while holding a bottle she had been passed by the person who started the violence.
"She had been hanging around with the wrong crowd on that night.
"She has since turned her life around and continues to make progress.
"She is ashamed, embarrassed and aware of the hurt and disappointment she has caused her parents."
