For the queen, White has rook, bishop and two pawns, but Black’s biggest problem is the weakness of g7. The attack is unstoppable.

Black resigned.

White blocks the f-pawn from moving.

But not 25.gxh3 Qc5+ 26.Kh1 Qc6+ 27.Kg1 Qc5+=.

On 25...Qc4+, White wins with 26.Ke1 (or 26.Ne2+–).

Not 26.Ke1 Qe5+, and Black wins.
Black resigned. There could follow 26...Bxe2+ 27.Ke1 (of course, not 27.Kxe2 Rfe8+ 28.Kf3 Qc6+ 29.Kg4 Qxg2+–+) 27...Qa5+ 28.b4, with inevitable mate.

Black’s hopes are exclusively tied up with advancing the f-pawn. The following typical blockading sacrifice prevents this.

Black has no way of meeting the white attack, and so he resigned.

The knight on d5 takes the important c3-square from the white bishop, and blockades the pawn on d4, which only disturbs White, by restricting his minor pieces.

He could also keep the advantage with 39...Bb4, threatening to penetrate the white position from the queenside.