Winning does not mean Won

There are no points for style in chess. Whether you win brilliantly or ugly, it is still only worth 1 point on the scoreboard. And it is the same for losing. You can accumulate all the advantages in the world, but it only takes 1 move to throw them away.
If the current zonal has demonstrated anything it is the 'Winning does not mean won'. Especially at the top end of the tournament there were a number of fortunate escapes where it seemed that clear advantages weren't enough to overcome title wielding opponents. The top two seeds seem to benefit especially, with draw offers being made by opponents in winning positions, and opponents walking into the only trick left in the position.
But to show you how easy it is, here is a game I played earlier this week. I am black and have played quite a smooth positional game to reach a clearly winning ending. The challenge is to find out how I managed to lose from this position. I played 1. ... Kb5 and then ....