White resigned.

The white Nd4 is clearly loose. It is not hard to see that it covers the f3-square. Thus, Black found the idea...

The most tenacious.
If the sacrifice is accepted, then after 21.gxh3 Rad8 22.f4 Rxd4 23.fxe5 Qxe5 24.Re2 Re6, followed by ...Rg6+ and ...Ne6, all Black’s pieces are attacking, and this attack assumes a decisive character.

As a result of the tactical operation, Black has won a pawn without any compensation. In addition, the white king is weak.

Unfortunately, Black lost a significant part of his advantage in time-trouble, by choosing the prophylactic 29...Kh7. Later, after mutual time-trouble mistakes, White missed a chance to win, and the game was eventually drawn.

With a winning position.

The battle is mainly taking place on the light squares. At the same time, the black king finds himself in an unpleasant opposition on the diagonal, and there are also checks threatened on e7 or h6. Checks against the white king get nowhere, and so a strong move is...

removing all threats and freeing the Be6.
The end of the game probably took place amidst time-trouble, and there followed instead 38...Be5+? 39.Kg2 (White wins with 39.Kh4!! Qe8 40.Bc6) 39...Bxd5+ 40.Rxd5 Qb7? (with mutually correct play, after 40...Qe6 41.Rxe5 Qxe5 42.Nxh6+ Kg7 43.Nf5+ Kh8 44.Qf2 Qd5+ 45.Kh2 Rf7 46.Qf4 Rh7+ 47.Kg3 Ne4+ 48.Kg2 Ng5+ 49.Kg3, a draw could result) 41.Ne3, and White won.

Black has a decisive attack.