[%c_effect e8;square;e8;type;GreatFind;persistent;true] Played after a thorough thought.
1. c2c4  1... e7e5  2. b1c3  2... g8f6  3. g1f3  3... b8c6  4. e2e4  4... f8c5 Black challenges his opponent on his own territory $1 5. f3e5  5... c6e5  6. d2d4  6... c5b4  7. d4e5  7... f6e4  8. d1f3  8... d7d5 [%c_effect d5;square;d5;type;Interesting;persistent;true] A fresh but risky line, according to the Azeri GM. 9. f1e2 The most reliable answer. White needs to complete his development ASAP. 9... d5d4 [%mdl 4][%c_effect d4;square;d4;type;Interesting;persistent;true] A promising side line. 10. f3e4  10... d4c3  11. e1g1  11... e8g8  12. a2a3  12... c3b2  13. c1b2  13... b4c5 This has been seen just once, and Caruana's next logical move turns out to be a novelty. 14. e2d3 There are no kingside defenders; therefore, this move is self-explanatory. 14... g7g6 A needed weakening, and White wants to capitalize on it at once. 15. e5e6 [%c_effect e6;square;e6;type;GreatFind;persistent;true] 15... d8e7 [%c_effect e7;square;e7;type;GreatFind;persistent;true] More or less the only move. 16. f1e1  16... a7a5 [%c_effect a5;square;a5;type;GreatFind;persistent;true] Solving the problem of the a8-rook. If it stays on its initial square, White would practically always have a decisive kingside superiority. 17. e4f4 Caruana prevents the activation of the black rook. At least for the time being. 17... f7f6 Solid play by Mamedyarov. Being a great attacker himself, he most likely did not even consider pawn-grabbing as an option. 18. d3e4 [%c_effect e4;square;e4;type;GreatFind;persistent;true] White is in time to force some concession. 18... a8a6  19. a1d1 But this does not look optimal. 19... a6d6 Black too could have been a tad trickier. 20. d1d6  20... c5d6 The problem of the black rook is solved; now the ball is in White's court. How to build the initiative $2 21. f4h4 No retreat $1 21... c7c6 Takes away the d5-square from the white bishop. Mamedyarov is ready to win the e6-pawn. 22. e4d3  22... d6a3  23. b2a3  23... e7a3 Mamedyarov has won a pawn but, what's more, has managed to trade another light piece. White needs strong threats, and he needs them now. 24. h4g3 The sacrifice on g6 is White's best hope.