Must Know Endgame

Can you find white's only winning play here?

7r/8/7P/1p3KP1/8/8/8/3k4 w - - 0 1

No. 1-1
  1. g6!! R:h6 2. g7 Rh5+ 3. Kf4 (the K must run away from the pawn else Black can pin it and win it, so it must get all the way down to the 2nd rank to prevent an X-ray) Rh4+ 4. Kf3 Rh3+ 5. Kg2 (finally). Now the Pawn queens, but there is still a whole lot of work to do.