Cheeky. If e5 Qxg2 is mate and in the meantime Black now has three pieces on e4.
18. f3
Puts an end to most threats by blocking the diagonal as well as reinforcing the e pawn.
18... Qg6g5
Avoiding a possible discovery on the queen by e5.
19. Ra1d1
Made on the general grounds that supporting the central pawn advance was stronger that going to the open file. White can take his time.
19... Nf6h5
Black fights hard to stay in the game by aiming for f4 and reviving the attack on g2.
20. Qa4a5
White offers a queen exchange on the grounds that he is two safe pawns up. And if the black queen retreats too far then white plays Qxh5.
20... f5
Desperate measures to prevent the exchange but now the pawn can't move as it is pinned to the queen.
21. Qa5b6
White takes aim at the loose bishop and the e pawn
21... Nh5f4
Black loses concentration. This defends the e6 pawn as well as threatening mate but loses a piece. I thought he had to play Bc8 when white can continue building with Bc4 and d5.
22. Bc7xf4 Qg5xf4 23. Qb6xb7
With the loss of the piece the black counter attack is more or less over.