Doctors fear a Tottenham Hotspur fan could be left with permanent damage to his eyesight following an attack by a fellow Spurs supporter - who apparently mistook him for a Chelsea fan.
Michael Voller was assaulted after his team's FA Cup semi-final defeat to Chelsea on Saturday at Wembley.
He was set upon after the match outside an Indian restaurant near the stadium.
He was punched in the face and suffered a broken skull and damage to his cheek-bone and eye-socket.
Mr Voller had been walking with a group of friends past Moore Spice Indian restaurant on Engineers Way at about 19:30 BST, The Met Police said.