Friday chess puzzle 14: the solution

Last week's chess puzzle was from 1893 and Tarrasch's match with Tchigorin.

From the position above (after 20 moves), Tarrasch found the following mating finish:

21 Rxf6!! Kxf6; 22 Bg5+ Kg7; 23 Qh6+ Kg8; 24 Rf1 Rf8 (... Rb7 holds off the mate, at the cost of the rook); 25 Bf6 Qxf6; 26 Rxf6 resigns (the threat is 27 Rxg6+ hg; 28 Qxg6 mate)

Congratulations to Chris Wardle, Karlheinz Vogel and Paul Dargan, all of whom found the initial move.