With a rook pawn still at home, the attacking king must run up the board ahead of it to reach g7 before the defender reaches the corner; pawn moves and sideways king moves lose the race.
A position from the game Panno–Najdorf (1968) that has become a standard test. White has only a rook pawn on h2 and a king on h3; Black's king is on b7, far away. Is this a win?