A policeman who fractured a football fan’s hand by hitting him with a baton has been reprimanded for misconduct.
The Birmingham City supporter was injured as he filmed police outside Villa Park ahead of a derby clash in September.
The West Midlands Police officer said he struck the man amid a volatile situation and feared for his safety.
He will be retrained in first aid and the use of force, the police watchdog said.
The Independent Police Complaints Commission (IPCC) conducted an investigation after the supporter, described as Mr A, claimed he was the victim of excessive force.
The unidentified officer, known as PC K, was with a unit responsible for moving Blues fans to Villa Park before the game, where a high level of disorder was expected.
Mr A was among a large crowd escorted to the ground before they were stopped by police near some gates, behind which where Aston Villa fans.
He said the crowd was amicable and he began filming them on his iPhone, which had emitted a bright light.
He said he was then struck by something on his left hand and dropped his phone.
He was later diagnosed with an impacted fracture.
Evidence from PC K and British Transport Police staff said the crowd was aggressive with “a definite intention to be violent”.
PC K said he was temporarily blinded by a light close to his face. He said Blues fans had used “flashbang” grenades earlier and thought the light was a similar device.
He said he raised his baton and used enough force “to get that light out of my eyes”.
The watchdog concluded the officer had a case to answer for misconduct over the force he used, but no criminal offence had taken place.
West Midlands Police will give the officer training, the IPCC said.