A right, a left and then Greco KO!

Right 10 ... Nd4. Left  11 ... Ng4. KO 13 ... Nxf2. My opponent never saw it coming and neither (to be quite honest) did I till the last minute otherwise I might have tried 10 ... Ng4 in the first instance! But in retrospect 10 ... Nd5 was needed to hold the pawn on f5.