Mok's missed endgame win

In the third round, Mok had 2544 rated grandmaster Sulskis Sarunas of Lithuania on the ropes

White to move

Mok is a pawn up and have the superior minor piece. Mok played 48. Kd3 and eventually drawn.

Instead he had a forced win. 48.Nd6+! Ke6 49. Nc4 Bg1 50. Ne3!

Now the white king cannot be prevented from reaching e4 which is winning. e,g 50... Kd6 51. Kd3 Ke6 52. Ke4 Bf2  53. Nc4  Bd4 54 b5 axb5 55. axb5 and now black is in zugzwang and must allow the white king into d5

From the first diagram, after 48.Nd6! black can also try 48...Kf4 but this is also lost. 49.Kf2! controlling g1 so the bishop will be unable to defend the b6 pawn. 49...Bg3 50 Kf1 Bh2 51. b5 axb5 52. axb5 wins.