Chess puzzle (Checkmate)
Moves: 1. d4 c5 2. c4 g6 3. Nf3 Bg7 4. e3 Nf6 5. dxc5 Qc7 6. Nc3 Qxc5 7. Bd3 Nc6 8.
O-O Nb4 9. a3 Nxd3 10. Qxd3 O-O 11. b4 Qh5 12. Rb1 d6 13. e4 Bg4 14. Nd5 Rac8
15. Nxe7+ Kh8 16. Nxc8 Rxc8 17. Ng5 Kg8 18. h3 Be2 19. Qxd6 Bxf1 20. Kxf1 Bf8
21. Qxf6 *
Position (FEN): 2r2bk1/pp3p1p/5Qp1/6Nq/1PP1P3/P6P/5PP1/1RB2K2 b - - 0 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 864
Best move: Qd1#