A lucky win at chess

A quick look at this position shows that white (that's me) is three pawns down in the ending and that black's pawns are well placed in the middle of the board.

Normally that would be enough for an easy win for black but I kept the queens on in a desperate attempt to get a draw through repeatedly checking the black king.

I offered black a draw several moves ago but he declined thinking (probably correctly) that he could force one of his extra pawns through.

The luck came when black made the mistake of moving his king away from his queen which meant that his queen could not block checks from my queen.

This mistake was compounded when the black king moved to the edge of the board where its movement is severely restricted.

My previous move was to take my king from g2 to h3, stopping his king from moving to h2, which meant that suddenly my manic attempts to drawn the game were rewarded with a simple win.

The only move that black had to delay the checkmate was to play his queen from e2 to d2 to put me in check but playing my pawn from g3 to g4 blocked black's check and inflicted one of my own. (This is the position shown here.)

Black's only legal move in this position is queen takes pawn on g4 to which I would reply queen takes queen which delivers checkmate. So black resigned and I am one lucky bunny.