The One that got away !
Well if fishermen can boast about 'the one that got away', why not chess players ?! Thanks to Oran_perrett for finding the winning move which I failed to find both OTB and in subsequent analysis. Was somewhat 'mesmerized' by 21. Rxd7 which doesn't go anywhere.
From Oran_perrett: 21. Rxd7 is not the best move, the simple 21.Nxh7 is
(Had originally posted this in the forum "Post your best Miniature".)