Pinned - An Original Chess Puzzle By ankitkiran

Hello and welcome back once again to my blog where I have an interesting puzzle to share which came directly out of a friend's game. In the game, my friend's opponent misjudged the situation resulting in getting checkmated, but the game was lost anyways immediately after white played a crushing move. Here is the puzzle:

And here I have posted the actual game in which this puzzle occurred although in the game, black captured with the pawn and immediately got checkmated on the next move. As a bonus to ankitkiran for sharing this puzzle with me, I have included my analysis with the game diagram as well:

Thanks for reading!