Blunder (7)

In the diagram position from Bezold - Shirov (Bundesliga 2009) Black blundered with his last move 15.- Nf6-d7??


Now White wins a piece with 16.d5 and Black resigned (for example 16.- Bxg5 17.dxc6 Nxc6 18.Nxg5 Qxg5 19.Rxd7 +-).