Daily chess puzzle: Check Mate #21

Another puzzle from Dragoslav Andric’s 1981 book “Matni Udar”.

Black to play and win

Kostrovicki v Chigorin, Petrograd 1875

Solution

Pretty: but a single forcing line, so not hard to see.

1…Rg3+ 2 hg[] Qh1+! 3 Nh1[] Rg2 mate.