Here is one that went the other way. I am white and it is black to move. I am a minor piece down and my king is under attack but I do have a threat of my own.
My opponent has many moves, Qf8 works and my position is rather hopeless.
However my opponent played Qf7?? after which I hit him with Nxd6+ and he promptly resigned.
smart fork man
In this position I was white and in spite of my opponent having a bishop I am totally winning. I've played 2 poor moves in the last few moves according to the engine and could have totally wiped him out if I hadn't made those but in this position I should still win, a simple hxg4 leaves me too many pawns too advanced for him to cope with.
But I decided to pin his bishop and follow up with f7 but totally overlooked that my opponent can play Rf3+.
Just a simple hxg4 and I'm covering f3 and he's totally tied up and I'm totally won.
Boy that gotta hurt