Hit by a sudden blow, White does not find the inner strength to put up serious resistance, and he loses easily. More tenacious was 24.d5, although here too, after 24...Rh6 25.Nf3 (on 25.e5, there follows the simple 25...Bf8, and the pawn on d5 is undefended) 25...Nd3 26.Re2 Nxb2 27.Rxb2 Bc5+ 28.Kh1 f5, Black breaks up the white centre and wins a pawn.

The black pieces are insufficiently active to support the hanging pawns, and White uses a tactical nuance to attack them:

The white knights joins the attack on the central squares.

On 18...Nf6, there would follow 19.Nb3 Nd7 (19...c4 20.Qxe7 Rxe7 21.Nd4 gives White an excellent post for his knight) 20.Rc3, followed by Rf1-c1 – defending c5 is not easy.
Black is prepared to defend the c5-pawn, but White finds a new target in his camp, and switches to an attack on the light squares.

20...dxe4 would leave too many pawn islands in the black camp.
On 20...c4, there would follow 21.Qh3, with the idea of a blow against the light squares with b2-b3.
It was essential to maintain the tension on the central light squares. Correct was 20...Nf6, after which White only has a minimal advantage.

Black’s kingside, with its weakened light squares, is undefended, and White easily develops the initiative.

The Nh7 loses its last hope of coming into the game, and Black has no counterplay at all.

Black resigned.

White’s position is better, but at the moment, the black pieces are harmoniously placed, and are able to hold the defensive lines. The next move is designed to provoke disharmony in Black’s position.

It turns out that Black must weaken his position with a pawn move.