The Pilgrims, playing on the main Jakemans Community Stadium pitch, suffered a 9-1 defeat to York City.
Owen Sheriff scored United's goal - with fellow defender Taylor Jaine sent off for two bookable offences.
Boston (3-4-2-1): Cameron Fox; Taylor Jaine, Owen Sheriff, Lucas Stubbs; JJ Ward, Rueben Fogg, Jake Henderson (Will Langford 12), Josh Doran; Han Stevens, Lucas Turrell (Oskar Rajski 46); Krisztian Gagyi (Flynn Slater 68). Sub (not used): Jake Lovelace.
Referee: Alistair Wilson.