Having momentarily lost attention, Black has just carelessly doubled rooks on the d-file, another illustration of the fact that even the very greatest players sometimes make childish mistakes. In reply, there followed a simple blow, which became possible because of the insufficiently strong black position on the light squares.

Black resigned.

White has an extra exchange, but the Nd4 can be pinned, and the dark squares in his camp are not very strong. After the incautious:

it turns out that the opposition of the queens is in White’s favour.
It was essential to increase the pressure with 21...Bc5!. White would have to fight for equality: 22.b4! (he cannot solve his problems with 22.Rd2 Rd8 23.Qb3 (23.Rad1 Nxb2 24.Nc6+ Kc7 25.Rxd8 Bxe3–+) 23...Rxd4 24.Rxd4 Bxd4 25.Qxa4 Bxf2+ 26.Kh1 Qxb2 Black has the advantage, since the e5-pawn is also an object of attack) 22...Bxb4 23.Qb3 Bc3 24.Rac1 Bxd4 25.Qxa4 Bxf2+ 26.Kh1 Be3 27.Rc3 Rc8. The e5-pawn is weak, and Black’s chances are preferable.

There is no defence against the Rf1 being brought in, so Black resigned.

The Bd5 is X-rayed by the Bg2, but defended by the Ne7. With the help of a piece currently standing on the edge of the board, White gets through to the target:

It should be noted that, in such positions, a knight on h4 has no other prospects than a possible jump to g6.

The light squares in Black’s camp are creaking, and so he is defenceless.

Black resigned.

Black has incautiously placed his queen on c7, which White exploits: