After 55...Rb2, we got the following position in Karjakin - Anand (Candidates 2014, round 13). Well, how about Nxg5, does it work?
[White "Karjakin"]
[Black "Anand"]
[FEN "8/8/6k1/4p1p1/4P1Pp/5P1N/1r1BK3/8 w - - 0 1"]
1.Nxg5 Rxd2+ 2.Kxd2 Kxg5 3.Ke3 h3 4.Kf2 Kf4 5.Kg1 Kg5 6.Kh1
Seems better (winning?) for white. Am I missing something?