Checkmate with one move.
(Excuse me for my english. I use google translator and please take into consideration, that I write from the perspective of a player with elo 1700. My observations may not always be correct.)
It is not a miraculous move. Interest only for fun!
Math is sometimes called the situation when a player gains decisive the upper hand. In this sense, I really win with checkmate after one move. I played with black. In blitz chess opponent was so fired up that played rashly and probably missed right area. So I managed to make only one move and the opponent must resigned.
Yet there is a lesson. Do not be rash and keep right computer mouse :-)