Mikey Dye lost his life outside Wembley in September before the England v Wales Euro 2012 qualifier.
Mytton has been remanded in custody and admitted his guilt via video link to the Old Bailey. He will be sentenced on December 21st.
The court heard Mr Dye was taken to Northwick Park Hospital in north-west London with blunt force trauma to the back of his head at 7.20pm, but died shortly after his arrival.
RIP Mikey Dye.