Black to move!
The ending arose from a drawn R+P vs B+N ending. Of course, white could make no progress with the pawn because of the bishop's control of the g7 square, so Ding sacrificed the rook for the bishop at f6 in a last attempt ploy to hoodwink Grischuk, but Grischuk was well aware of how to draw the position anyway.
I liked the puzzle. It's simple but instructive.
a) 2. Ke5 Ne7, 3. g7 Ng8 =
b) 2. Kf7 Ne3!, 4. g7 Nf5!, 5. g8=Q Nh6+ (fork check - Black draws) =