The Red Imps' full-back fired home a spectacular 20-yard set-piece, which gave keeper Ashley Timms no chance, in the 87th minute to settle the encounter in his side's favour in a match dedicated to the memory of their former chairman.
United were excellent for long spells, with defensive trio Stefan Galinski, Scott Garner and Carl Piergianni in dominant form alongside an imperious display of front-running from Ricky Miller.
Piergianni had a stoppage time equaliser harshly ruled out for pushing, while Miller was denied by a terrific Paul Farman save before the break.
Boston (3-5-2): Ashley Timms (Sam Vince 90); Stefan Galinski (James Reed 78), Scott Garner, Carl Piergianni; Peter Bore (Spencer Weir-Daley 73), Ian Ross (Ben Fairclough 83), Conor Marshall, Ben Milnes, Netan Sansara (Nathan Fox 73); Marc Newsham, Ricky Miller (Charley Sanders 83).
Referee: Andrew Park