Good Wörishofen (part eight)

IN round seven I grabbed a pawn, only to come under a strong attack that should have been decisive.
Neither player found the best moves, but Black later won his pawn back and still had powerful pressure.

Position after 56.a6 in Spanton (1901) - Boris Litfin (1978)

Black wins with 56...Qxb5!, eg 57.Qxb4 Qxa6+ 58.Kb2 Re2+ 59.Rd2 Qxd3 (Stockfish9).
Instead, BL won a piece by 56...Bc3+ 57.Ka2 Qe2+ 58.Ka3 Rxd3 59.Rxd3 Qxd3, but after 60.a7 Qe4 61.b6, he played 61...Qe7+? (61...Qc6 would have drawn) and lost following 62.Ka4 Qb7 63.Qb5+? (63.Qc4 wins easily) Kf8? (63...Kg7 seems to draw) 64.Qc5+.
At this point, in time trouble, BL picked up his queen and tried to play 64...Qa6+. The game finished 64...Qe7 65.Qxe7+ Kxe7 66.a8Q (1-0).