I'm not going to hold back in a grappling match and I'll break my cocky opponent's shoulder.
Why do you want to hurt your opponent so much? Is there a problem behind you wanting to hurt your opponent? Tell me more about it.
I haven't had any chance to win against him. I will hurt his shoulder so that I can win.
Even though you want to win badly, you should not hurt your opponent on purpose. Hurting your opponent would cause them great pain and it would take a long time for them to recover.
This is only a grappling match, I'm not going to hurt him that bad and it is my victory if I break his shoulder.
Even if the harm was just little, it's still harm and it will give you an unfair advantage with the game, and it will make you winnings invalid. Moving forward, I suggest that you just practice harder so that you have a better chance to do so in the contest.