It’s an exciting endgame: 3 pawns (Carlson) vs a piece (Naiditsch). Carlson storms the king side with 4 pawns and a rook and against a lone pawn and king defending, while Naiditsch’s QRP makes an end run on the other side of the board.
Here is a link w/ commentary:
http://en.chessbase.com/post/grenke-rd3-naiditsch-beats-carlsen-again
It's Carlsen's 10th Move that kicks the game off.
Apparently 49...Rf4 instead of 49...Kf6 is the move that draws.
The jury is still out on whether Carlsen paid the penalty for trying
to win a drawn game. But most suspect that is the case.
And why not? Turning book drawn endings into wins seems to be one of his trademarks.
Arkadij Naiditsch vs Magnus Carlsen, GRENKE ,2015