Seven people have been arrested during clashes between fans as Brighton and Hove Albion faced Crystal Palace.
The arrests were made for offences including assault, assault on an emergency worker, affray and offences contrary to the Public Order Act - including two aggravated by homophobia.
One officer was injured before kick-off by what is believed to have been a 'thrown pyrotechnic'.
Sussex Police said the officer did not require hospital treatment.
There was an increased police presence in Brighton city centre ahead of the game, which Brighton won 4-1 at Amex Stadium.