Rome Police say dozens of masked hoodlums attacked Tottenham fans out drinking ahead of their Europa League match against Lazio, sending seven of them to hospital.
Police say they detained some of the 50 hoodlums but others got away after trashing The Drunken Ship' pub in Rome's Campo de' Fiori square, a popular drinking spot.
Blood-stained the cobblestones outside the bar, and stools and tables were overturned.
The aggressors were believed to be Lazio fans; they all had their faces covered by motorcycle helmets or scarves.
The brawl began sometime after 1am and was over within minutes. Police said those hospitalised were British men, aged 20-60.
Lazio hosts Tottenham at the Stadio Olimpico on Thursday in Group J.