A missed opportunity

I recently watched a game between two players ranked in just under 2000. As the endgame came along, both played relatively quickly, especially considering the amount of time, well  over 10 minutes, each had left. Finally, a point came where I saw what I thought to be a complete blunder, where white let a win slip away (see the revised analysis on the fourth post. He actually could have only drawn the game). I struck up a conversation afterwards with the black player, who quickly dismissed my idea, and because of our rating differences, I was quick to agree. After pondering for a while, however, I believed I had found a winning continuation, shown below.

I actually missed the move 43. ...Nf4 which saves half a point after 44. Ng1 Nh3 45. Ne2 etc.

After 41 Ng1, Black could play g2 followed by retreating his knight to take care of any threats from the white pawns.  White's knight has to babysit to avoid the G-pawn promotion, and Black, after taking care of any promotion threats if he has to, can then just march his H pawn down. (And the second G-pawn means that White can't do anything useful with that knight as far as blocking the H-pawn.

The issue there is that a sigle knight cannot handle the knight and pawn duo, leading to what I find as a drawn game.

Well, here's some more thinking I did.

by theway my analysis is 100% correct

Which is why there was the rating difference in the first place. Many thanks for the responses.