Knight Deflection

Only a few days ago, I was studying knight and pawn endings and one of the themes in this kind of ending is the deflection of the opponent's knight away from a passed pawn. When the opportunity actually came up to apply it, I missed it and chose instead to chase the knight away. Here we are at the critical moment when I should have played 53... Nd6+. White must capture the knight to avoid a quicker loss. Analysis shows that the winning line will be 54. Nd6 h3 55. a5 h2 56. Ka7 h1(Q) 57. Kb6 Qh6 58. Kc7 Qg7+ and from here on black will have to maneuver his queen and king to the queenside through a series of checks for the win albeit a difficult one.