Lansdown fell to an agonising four-run defeat against Shapwick & Polden in the Bristol and Somerset division.
Anant Tambvekar took 4-27 to put Shapwick on the back foot, with support from Chris Day (2-21) and Sam Bowery (2-20).
Wayne Spencer provided some resistance as he tallied 56, only for Tom Hankins to end his threat as Shapwick were dismissed for 187.
At 89-3 and with Jordan Smith well set, Lansdown looked in good shape, but they were pegged back as regular wickets fell.
They needed just 14 to win with four wickets in hand, only for Shapwick to skittle out the tail and seal the win.