I was playing a 5-minute game on ICC tonight. I had a winning endgame, but the problem was that I was down to 1 second on my clock (Yeah I know, I need to move faster), and my opponent had almost two minutes. No problem, I thought. I will just promote my pawn to a Queen and sacrifice it for the pawn on g6 and get a draw.
In the picture above, I have just played 57. a7, and I premoved 58. a8=Q. When my opponent played 57...Ne6???, my BlitzIn made a DING sound to indicate the game was over. Turns out that 58. a8=Q was checkmate.