The Pilgrims were beaten 4-0 by a vibrant King's Lynn side gearing up for life in the Evo-Stik Premier Division.
Two first half thunderbolts from Jordan Yong and a George Thomson penalty, plus an Andy Hall strike eight minutes after half-time, handed the Linnets a deserved victory against a lethargic United side.
Boston (3-5-2): Sam Vince; Conor Marshall (Ben Fairclough 39), Scott Garner, Stefan Galinski; Peter Bore, James Reed (Alex Meaney 53), Ian Ross (Charley Sanders 60), Ben Milnes, Netan Sansara; Spencer Weir-Daley (Marc Newsham 53), Ricky Miller. Sub (not used): Ashley Timms (gk).
Referee: Alistair Wilson