Television pictures showed that Luiz Carlos Silva landed several punches at the shirtless supporter who invaded the field in injury time of Sunday's America-Atletico Mineiro derby in Belo Horizonte.
'Everything I did yesterday I did conscientiously and I would do it again' Silva told Brazilian media on Monday. 'I'm a self-employed worker and if that guy had landed a punch I could have been off work when I've got five children to raise.'
'I had to defend myself and I did it by going onto the attack.
'If I had run away it would have looked bad. I was not prepared to suffer this embarrassment with my children watching (on the television).'
The incident sparked a five-minute brawl as Atletico Mineiro players tried to protect the supporter from the police.
Atletico goalkeeper Danrlei accused police of attacking him as he tried to intervene.
The match was in the Mineiro (Minas Gerais state) championship one of the many regional tournaments which kick off the Brazilian season. America won 1-0 in a game which also produced three red cards.
Meanwhile Atletico launched another protest against refereeing in the competition and repeated demands for referees from outside Minas Gerais state to officiate their games.