Okay so, for me this isn't an honor question, for me it comes down to basics. What are you doing? If the answer is fighting, then fight. Nobody ever got better fighting those who were constantly less skilled than they, nobody improved if their opponents were always nerfed. "Fair play" is all well and good but we are talking combat. Let's take a look at what the word means, it means the art of fighting, war, death, dismemberment, destruction of your opponent so that they don't destroy you. In no war or duel that I have ever heard of in history did one fighter stab another in the leg and say, "Oh sorry mate, let me hop around on just my own leg so it's fair." When you "take off" another dude's leg then keep fighting to win, that is what a competition is. There is a winner and a loser. You don't have to be rude about it, you can congratulate your opponent after for doing as well as they did, give advice if needed, and just all around appreciate the fun of competition but this whole dumbing down your own skill to match another fighter kind of kills the whole point of what you are doing in the first place.
Always strive to improve, always respect your opponent, and always remember that there is always someone out there who is better than you. That is what my thoughts on this are anyway, I invite respectful debate.