[%c_effect h6;square;h6;type;GreatFind;persistent;true] This is the point of the sacrifice.
1. d2d4  1... g8f6  2. c1f4  2... e7e6  3. e2e3  3... c7c5  4. g1f3  4... f8e7  5. h2h4 A surprising advance and a theoretical novelty, according to my database. It's not shocking that the calmer pawn advance to h3 is the most popular move. I'm not sure if this move was part of his home preparation or the result of over-the-board inspiration, but Gukesh's courage and creativity must be praised. Compared to 5.h3, the move played also opens up space so that the bishop is not attacked with Nf6-h5. However, White already indicated that his plans involve castling queenside and advancing pawns on the kingside. 5... b7b6 [%c_effect b6;square;b6;type;Inaccuracy;persistent;true] Choosing a move is hard when there are so many options. Gukesh's strong reply shows the flaws with Black's move. 6. b1c3 [%c_effect c3;square;c3;type;GreatFind;persistent;true] Another move that ignores aesthetic prejudices. The knight heads to b5 and also supports the d4-d5 advance. 6... c5d4 The alternatives are not enough to equalize. White retains pressure in all following alternatives: 7. f3d4 [%c_effect d4;square;d4;type;GreatFind;persistent;true] The only way to fight for the initiative. The queen will be developed on f3. White's pieces are very active. 7... e8g8  8. d4b5 [%c_effect b5;square;b5;type;Inaccuracy;persistent;true] This is a tempting move, but objectively it's stronger to prioritize development with 8... f6e8  9. d1f3  9... b8c6 Black can complete his development now. 10. e1c1  10... c8b7  11. h4h5  11... a7a6  12. b5d6  12... e8d6  13. f4d6  13... f7f5 In many positions, Black will have the chance to play h7-h6, and he should have done so at some point. 14. f3g3  14... b6b5  15. d6e7  15... d8e7  16. g3c7  16... b7c8  17. g2g4 [%c_effect g4;square;g4;type;GreatFind;persistent;true] Opening the g-file to create attacking chances. 17... b5b4  18. c3a4  18... f5g4  19. c7g3 It's never quite clear whether White should insert h6-g6, but the computer normally likes to do so. 19... d7d5 [%c_effect d5;square;d5;type;Inaccuracy;persistent;true] This shuts down the bishop's diagonal and creates problems for Black. 20. f1e2  20... a8b8 [%c_effect b8;square;b8;type;Inaccuracy;persistent;true] 21. h1g1  21... c8d7  22. e2g4  22... g8h8  23. c1b1  23... c6a7 [%c_effect a7;square;a7;type;Mistake;persistent;true] This move will be exemplarily punished. 24. a4c5 [%c_effect c5;square;c5;type;Brilliant;persistent;true] A brilliant combination, which will certainly find its way into future tactics exercise books. 24... e7c5  25. g4e6  25... c5e7 