Up to 200 'fans' clashed outside Cleethorpes Pier with bricks and bottles thrown, however Superintendent Dave Hall was pleased with the policing operation.
Superintendent Hall said: "It was very pleasing to see that the over whelming majority of the over 8000 people who attended the FA cup match at Blundell Park, between Grimsby Town and Scunthorpe United did not cause any concern to police officers and all people left the ground safely.
"Police made six arrests before and during the match for football related incidents which included two people arrested for pitch invasion and others for breach of Football Banning orders and public order offences.
"Following the match, as police made attempts to direct Scunthorpe United fans safely away from Blundell Park, an altercation took place between a large number of individuals.
"These people are believed to have been both Grimsby Town and Scunthorpe United supporters. One person sustained injuries in the incident and left the location before receiving any treatment.
"A further six arrests were made following this altercation and these people remain in police custody".