The Breakthrough in Pawn endgames

The breakthrough is chess a very important issue. It can happen in every phase of a game but mostly it happens in middle- or endgames.

Very well-known is the breakthrough in pawn endgames. One meaning of it is creating an unstoppable passed pawn. A decisive fact is  the absence of the opponent`s king

Is it possible to stop this breakthrough? Yes, it is if black has the move right:

So let us put the pawns one row higher and try the direct breakthrough again:

So is it a drawish position? No!:

Finally a breakthrough in a mastergame: