In view of the unavoidable mate in 2, Black resigned.

The exchange of all the major pieces is not so terrible for Black, because he has an outside passed h-pawn. But all the while, the white king remains safe, and it is uncomfortable for Black to continually watch his weak back rank. Therefore, Black gives up one of his doubled pawns, to break up the white king’s cover.

The knight comes to d5 with tempo – this is the ideal square for the attack.

This move, ensuring the b3-square for his major pieces, decides the outcome of the game.

White resigned.

Usually in such an open position, the player who is attacking with checks wins. After the natural queen promotion 46...e1=Q+ 47.Kh2, Black has no more checks, and White will launch a decisive attack on his next move.
However, Black found a move White had overlooked (instead of his last move 46.a7-a8=Q, White could have won by 46.Kh1-h2!).

And White resigned, because after 47.Kh2, there follows 47...Ng4+ 48.hxg4 Rh7+ 49.Kg3 e1=Q+ 50.Kf3 fxg4+ 51.Kxg4 Rh4+, mating.

White’s initiative looks very powerful, but Black has a whole extra piece. On 24.Rh8, there follows 24...h5, and there is nothing concrete. But White has available a brilliant tactical resource, involving luring the black queen to the seventh rank, where it can be attacked.

If 25...Qd7 26.Rxd7+ Bxd7, White has many attacking resources, one of which is 27.Bc3 Re8 28.Qd2, with the threats of g2-g4 and Qd2-g5, and a decisive attack on the dark squares.

Winning.