Battersea Club Chumpion

MY bid to become champion of Battersea Chess Club suffered something of a setback last night, despite my opponent offering me a golden opportunity when I was a piece-for-a-pawn down.

White has just played 40.Kg2-g3?? in Tim Valentine (134) - Spanton (171)

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40...g5??
This is easily parried.
Analysis engines have no trouble finding 40...Qc7, when White cannot save the knight, so Black has serious winning chances.
The game finished: 41.Qf3 Kh7 42.Bxg5 Bxg5 43.Qxf7+ 1-0