The white pawns easily promote.

Naturally, the black knight would like to come to d5, but if it does so at once, he must reckon on the exchange on d5, creating a kingside pawn majority for White. There is also the idea of the bishop coming to g4, followed by the advance of the h-pawn. In both cases, White obtains counterplay. Therefore, Black goes in for a sacrifice, with the help of which he obtains an excellent post for his knight on d5, whilst also devaluing the white kingside pawn structure.

Black will transfer his rook to f5, from where it both defends and attacks.

The Bg3 is terrible, and Black’s position is winning.

White resigned.

With the help of a typical positional pawn sacrifice, Black obtains a magnificent outpost in the centre, whilst the white bishop on c2, being so badly restricted, is very bad.

No better was 23.fxe4 Bxc3 24.bxc3 f4.

Under the cover of the Ne5, Black quietly prepares a decisive attack. White has nothing with which to oppose it.

White is suffering, so he might as well have something to suffer for! More practical chances were offered by 31.Bxa4, although after 31...g4 (Black also has a dangerous attack after 31...f3) 32.Bd1 Kh7!, with the threat of 33...f3, Black should win in any case.