I enjoyed watching the video while following the moves from the database in a separate window, you can do that too!
If you are curious how Grachev lost the endgame that was drawn all along, here is the culprit move/position:
Black to move.
Grachev blundered with 51… Kc8? and later the pawn advanced with a decisive tempo.
As pointed out by computer - correct was 51... Kd8! 52. Kb6 Rh2 53. Rg8+ Ke7 54. c6 Rb2+ 55. Kxa5 Rc2 56. Kb6 f3 =
When you are playing against Kramnik – any position is full of tricks!