A judge threw out the case against a teenager accused of throwing a beer can at police outside a party invaded by 200 gatecrashers after it was advertised on Facebook.
Ashley Pemberton, of Fairfax Road, Farnborough, Hampshire, was charged with affray and using a beer can as an offensive weapon.
The jury at Winchester Crown Court was shown video footage taken from a police helicopter which the prosecution claimed showed Pemberton throwing the can.
But Judge Guy Boney acquitted the 19-year-old and formally found him not guilty of both charges.
The case came after 200 people turned up to the party in Chapel Lane, Farnborough, Hampshire, on July 18 last year.
A brawl involving 30 people broke out, which took police more than two hours to calm down.
Keith Berger, 19, of Oaken Copse Crescent, Farnborough, pleaded guilty to affray and James Mahabeer, 18, of Cambridge Road, Aldershot, pleaded guilty to a public order offence at an earlier hearing.
They will be sentenced on a date still to be set.