Violence began at West Bromwich Albion after Wolverhampton Wanderers away fans got tickets in home areas and were caught celebrating their team's second goal.
Play in the Black Country FA Cup derby at The Hawthorns was suspended for more than half an hour after trouble flared in the stands and fans spilled onto the pitch.
West Midlands Police confirmed six arrests were made following the second-half chaos yesterday and one person was taken to hospital with head injuries.
Fans clashed with officers and some players feared for relatives sitting near the trouble - with West Brom's Kyle Bartley going into the crowd to get his children out.