If another person (muslim or non muslim) demands a fight with you and you tell him "No" repeatedly but he won't listen and then attacks you with a punch or kick etc. are we allowed to fight back? Will Allah (SWT) protect us?
Are you, perhaps, being bullied in school? Or is the bullying happening outside of school?
I'm asking because, in either case, this can be solved without you having to reciprocate the harm. They don't have principles and guidance counselors in schools for no reason, if you're getting harassed then go report the fool. Bullying should not be tolerated.
If it's outside of school, I say involve your parents. Your parents can get in contact with the kid's parents and they'll handle him. If that doesn't work, then, again, involve the school principle and he might just get suspended. No one likes getting suspended as it goes on the school record so hopefully he'll learn his lesson.
That is if the bully is a non-Muslim.
If he's a Muslim, which is just plain sad, advice him gently. Remind him that Muslims don't act in such manner. Muslims know how to control their temper. Shaytaan is the enemy, not you. The fact that he wants to fight makes shaytaan happy - he wants to cause enmity and hatred between the two of you.
Basically, return that hate he might have for you with love. Try to avoid getting angry quickly and letting him rile you up. Obviously he's in the wrong, but try to understand him. What is his reason for wanting to fight so badly? Have you done something to upset him? Is he going through a rough time and he's just taking it out on you? Is he friendless and is maybe looking for attention? Maybe, and this is absurd, but maybe...he wants to fight you just for workout purposes? (crazy, I know, but 70 excuses...)
As the saying goes, "kill him with love".
If all else fails, whether he's a Muslim or not...then avoid him. Don't go to his "hangout" spots. Always walk with someone. Bullies usually approach loners (not outcasts but people who walk alone). I'm not saying become a coward and let him walk all over you (as some might accuse you of being), no, be a man but having a strong right hook doesn't necessarily make you a man... just try to avoid the trouble if possible.