I get frustated when people don't resign and end up losing

Game history is still down and I don't have the pgn but maybe I'll post it back here once it is.

Anyways, I am a 1600-1700 player at tournaments but when I'm totally focused I can beat 2000-2300 with moves that miracously come into your mind only when you are playing. However, these guys don't apparently like to lose against me, which I can understand.

What I can't understand is why they keep on playing instead of accepting defeat.

I was playing against a 2000 player and ended up having 1 queen and 1 knight (I think. Can't renember a lot because I've played other games since. I know I was either a rook or a queen up). His king spent all the game running exposed and he just would not give up. Ever.

Eventually I got mad and made a blunder that made me lose the game.

Questions being:
1. Do you think it's acceptable/ok for a player with this experience to push the game until the end just hopping that the minor ratting does a mistake? Wouldn't it be more 'fair-play-like' to admit defeat instead?
2. How to control such frustations?

I am a fan of someone resigning when I'm in a winning position. However, some people find it fun and challenging to try to win from lost positions and therefore have the right not to forfeit their right to a fighting chance. Therefore if you blunder a winning position then the game wasn't "in the bag" so to speak.

Ill get back to you.

Well it's purely your fault.
Of course it's fair to continue playing even when you are loosing.
But try to take it this way....your completely winning you have it in the bag and you have nothing to worry about.