4...Qf3+ 5.Bxf3+ Nxf3 6.Rh1+ Nh4 7.Nf6+ Kh6 8.Rxh4+ Kg7 9.Ne8+ Rxe8 10.Rxh7+ Kf6 11.Rxf7#.

Deflecting the rook from f8.

White had been counting on exploiting the tactical motif of the X-ray of the Rb1 on the black queen. However, he failed to appreciate the vulnerability of the f2-square, a pawn defended only by the king.

Black wins equally attractively after 21.Rxe7 Rxe7 22.Ba3 c3!! (22...Re5 23.Rxb6 Rxb6 24.Qa1 still allows White to resist) 23.Rxb6 cxd2 24.Rxa6 Rc1 25.Bf3 Rxd1+ 26.Bxd1 Re1+ 27.Kg2 g6 – the passed pawn brings Black victory.

The sacrifice of a bishop on this square is a typical idea, but it is rare to get a chance of doing so with the queen. The white king is forced to undertake a journey across the board, which will end in his death.

On 25.Rxe5, the inclusion of the bishop with 25...Bc8+ is decisive.

The trap closes. White resigned.

It is obvious that Black has a fine concentration of pieces around the white king. But where is the mate? Players with a sharp tactical vision will have no trouble spotting the finish.

The key idea.