Zinedine Zidane said on Wednesday he attacked defender Marco Materazzi during the World Cup final to defend the honour of his mother and sister.
The French captain said he could not let Materazzi's words on the pitch go unanswered, though he admitted head-butting the Italian was not a good thing to do.
In an interview with the French television channel Canal Plus, a chastened-looking Zidane also apologised to children and fans but said that he did not regret the attack which led to his sending off.
"He (Materazzi) pulled on my shirt several times and I told him that we could swap shirts at the end of the game if he wanted to," Zidane said in the live interview.
"He then pronounced very tough words, words that hurt me deeply, words about my mother and my sister. At first, I tried not to listen to him but he kept repeating them", Zidane said.
"I knew it was my last game and I knew there were only 10 minutes to play but things happened very swiftly," he said.
"I am a man before anything else."
Materazzi has denied mentioning Zidane's mother during the game in Berlin last Sunday.
Zidane, widely considered the greatest player of his generation, rammed his head into Materazzi's chest with the score at 1-1 and minutes to play in the second period of extra time.
The 34-year-old, who said the final would be his last professional game, was shown a red card and left the pitch in tears watched by his stunned team mates.
France, deprived of their leader and chief penalty-taker lost the game 5-3 on penalties.
Zidane denied Materazzi called him an Islamic "terrorist", as was reported by a Paris-based anti-racism group.
Born in Marseille in 1972, Zidane is of Algerian origin. His parents are from the village of Aguemone in the Kabylie region.
FIFA decided on Tuesday to open a disciplinary investigation into the incident and Sepp Blatter, head of soccer's ruling body, suggested Zidane could be stripped of the tournament's best player award.
The French playmaker said he was ready to face any disciplinary hearing and stressed that he was confident about the outcome.
"If someone can read (Materazzi's) lips, they will show that I'm telling the truth. The one who is really guilty must be punished," Zidane said.
"I don't want to attack anyone but I want to defend myself. I did something wrong and I was punished for that. I ended up alone in the changing rooms," Zidane said.
"But I was the one who was provoked and I reacted. It is always the one who reacts who is punished, never the one who provokes and this is not fair," he said.
Zidane apologised for his behaviour but he said he could not regret it.
"I know this is something that one should not do. I want to say that loud and clear because it was watched by two billion people and by millions of kids," Zidane said.
"I want to apologise to them but I can't regret what I did because it would mean that he (Materazzi) was right to say what he said.
"I have taught my kids to respect people and I have taught them that they deserve to be respected in return. I couldn't let something like that be said without any reaction."
Earlier Materazzi had denied making any mention of Zidane's mother.
"I said nothing to him about race, religion or politics I did not talk about his mother either," the defender was quoted as saying in an interview given on Wednesday to sports daily Gazzetta dello Sport.
"I lost my mother when I was 15 and it still upsets me to talk about it.
Of course I didn't know that his mother was in hospital. I send her my best wishes.
"Zidane was always my hero. I admire him greatly," Materazzi added.