There were only 19 moves and the guy found no other choice but to resign as the end of the game was already predicted!
Brilliant unexpected win!

White played a sloppy game. He wasted two moves in attempting fools' mate at the start and then retreating his queen.
He should have seen the dangers of your pawn advance much sooner.
He should not have resigned quite so soon. Bishop to b3 would have left still a little hope.
Another good example of a strong player under-restimating the abilities of a weaker on form player.
Well played

white's 19th move was the biggest mistake in the game :) 19.c4 and still black is better but white has some chances and against 1200+ player i would continue playing :)
I had an unexpected idea which I tried to implement and won as black over a guy rated 400 points above me!
Please leave your comments after the game!!
Thank you!