Boston beat relegation rivals Torquay even after going down to nine men late in the game.
Anthony Elding grabbed the winner, scoring from 10 yards after a mistake by Torquay defender Matt Villis.
Torquay pressed for an equaliser and Boston keeper Andy Marriott and Jamie Clarke both made goal-line saves.
In the last six minutes, Boston's Drewe Broughton and David Galbraith were both sent off for two bookable offences but the visitors held on.
Torquay: Abbey, Andrews, Woods, Villis (McPhee 55), Reed (Motteram 70), Murray, Mansell, Angus, Ward, Thorpe, Robertson.
Subs Not Used: Horsell, Hockley, Taylor.
Booked: Angus.
Boston Utd: Marriott, Clarke, Ellender, Miller (Galbraith 16), Tim Ryan, Rowson, Kennedy, Greaves, Broughton, Elding (Maylett 79), Green (N'Guessan 89).
Subs Not Used: Farrell, Richie Ryan.
Sent Off: Broughton (84), Galbraith (87).
Booked: Galbraith, Greaves, Broughton, Ellender.
Goals: Elding 41.
Att: 2,107.
Ref: P Crossley (Kent).