Sometimes it takes real skills to finish off a powerful attack. After 33 moves, White has chased the Black king out into the open and now can end the game with a few deft strokes.
A devastating shot that White unfortunately missed, most likely due to time trouble. Instead, he played 34.Nf7+? and allowed the Black king to help conquer its counterpart by marching all the way down the board after Kf4 35.Nd6+? (Best was 35.Qh6+ Kf5 36.h4 when White can still play for a win) 35…Ke3! 36.Qe7+ (Now 36.Qh6+ no longer helps because of 36…Ke2! 37.Qc1 Qd1+! trading queens with a dominant king in the ending; 36.h3 doesn’t help either because of 37…Kf2!) Kf2! 37.h3 Qd1+ 38.Kh2 Qg1#
34…Kh5 35.g4+ Kh4 36.Qh6#; 34…Kh4 35.Qh6#
35…Kxh4 36.Qf4+! (White could have won the queen with 36.Qh6+ Kg3 37.Qh2+ Kf2 38.Qg1+, but mate is probably better) Kh5 37.g4+ Kh4 38.g5+ K-any 39.Qg4#
Quiet, simple and crushing. The threat to mate on g5 is merely a prelude to the killer pawn advance. The less patient 36.g4+? doesn’t work because of 36…Kxh4 37.Qh6+ Kg3 38.Qh2+ Kxf3 and Black has slipped the noose.
36…Qd1+ 37.Kh2 or 36…h6 37.g4+ ends in the same way.
37.g4+ Kxh4 38.g5+ K-any 39.Qg4#