Simone Mastrelli, 30, has been jailed at Preston Crown Court for three-and-a-half years for the assault of Liverpool fan Sean Cox.
The Italian, who pleaded guilty, committed the crime outside Anfield before the Champions League tie between Liverpool and Roma last April.
Cox, 53, from Dunboyne, County Meath, was left in a coma following the attack, leaving him with severe brain injuries.
Mastrelli was extradited last month after being arrested in Italy due to a European Arrest Warrant.
Cox has been recovering at the National Rehabilitation Hospital in Dun Laoghaire.
Cox, who has three children, was left motionless on Walton Breck Road, Keith Sutton, prosecuting, said.
He added Mastrelli attempted to blend in with other travelling Roma fans, covering his face to conceal his identity. .
The court later heard that Mastrelli returned to the scene, changing his appearance and removing his clothes before entering Anfield to take in the match.
Liverpool won the first leg of the semi-final 5-2, with the Italians winning the return leg 4-2, leaving Jurgen Klopp's side progressing on aggregate to the final, where they lost to Real Madrid.
