A couple of checks to improve the position of the rook.
1. c2c4  1... g8f6  2. b1c3  2... e7e5  3. g1f3  3... b8c6  4. g2g3  4... c6d4 A relatively rare line, which Caruana also used some time ago. It seems as it is coming back into fashion these days at the top level. 5. f1g2  5... d4f3  6. g2f3  6... f8c5 The second main move. 7. d2d3 The main move is 7.0-0. 7... e8g8  8. e1g1  8... a7a5 Obstructing the opponent's queenside expansion well in advance with a novelty. 9. f3g2  9... c7c6  10. c1d2 Both sides accomplish their development and try to build play where they are stronger. Caruana intends queenside expansion, whereas Aronian is looking for a way to equalize in full with the help of the d7-d5 break. 10... d7d6  11. a2a3  11... c8e6  12. d1c2  12... h7h6 Last preparation. 13. c3a4  13... c5a7  14. c4c5 White strikes first. 14... d6c5 After some thought, Aronian decided to concede the bishop pair. 15. a4c5  15... a7c5  16. c2c5  16... e6d5 The point. Without the bishop pair, it should be equal. 17. f2f3 Therefore Caruana keeps both his bishops alive in a slightly awkward-looking way. 17... a5a4 Fixing some pitstops for both his pieces. 18. e2e4  18... f6d7  19. c5e3  19... d5b3  20. f3f4 White's plan is obvious. He will try to knock the e5-pawn down and clear the road for his unique bishop. 20... d8b6 Aronian decided that he will be better without the queens, but as we shall see, his dark squares will be in a greater danger in the endgame. 21. e3b6  21... d7b6  22. a1c1 Caruana plays in the most unpleasant way, consistently preventing the blockade. For the time being, the c6-c5 move is stopped. 22... f8d8  23. f1f3  23... b6d7 A new blockading attempt. 24. g2h3 Nope, it will not work. The second white bishop enters the field. 24... b3e6  25. h3e6  25... f7e6  26. g1f2 Patience is a virtue in the endgame $1 The king rushes to put the center in order. 26... c6c5  27. f2e2  27... b7b6 Now that everything is defended, White increases the tension on the dark squares. 28. d2c3  28... a8c8  29. f3f1 Patience again. 29... d8f8  30. e2e3  30... c8c7  31. f4e5 The time has come; Aronian's pieces are misplaced. 31... f8f1  32. c1f1  32... d7b8  33. d3d4 The key behind Caruana's strategy. It is not just the extra pawn that he is happy about. It is the nicer pair of pieces left on the board that will decide the outcome of the game. Some more files and diagonals are needed for these two to show their strength, and White presents them. 33... c5d4  34. c3d4  34... c7c2  35. f1d1 One last beautiful preparation. 35... b8c6  36. d4c3  36... c2h2  37. d1d6 White is wining. All his pieces are better than their counterparts, and he is about to start the harvest along the sixth rank. 37... c6a5  38. e3f3 Precision till the end $1 38... g8f7  39. d6b6  39... a5c4  40. b6b7  40... f7e8  41. b7g7  41... c4b2  42. c3b4 The rest is easy for Caruana. The knight is not a match to the white bishop. 42... e8d8  43. g7e7  43... b2c4  44. e7e6  44... h6h5  45. b4d6  45... h5h4  46. e6g6  46... h2h3  47. g6g8  47... d8d7 