Second half goals from Jamie Grimes (54) and Michael Gyasi (78) handed Paul Cook’s slick National League side a deserved win.
United threatened towards the end of the first half, but found Lucas Covolan and his Spireites rearguard in miserly form.
Boston (3-4-2-1): Rhys Davies; Lebrun Mbeka, Luke Shiels, Tom Platt; Ellis Myles, Brad Abbott (Ben Pollock 73), Will Atkinson, Alex Brown; Scott Pollock, Jordon Crawford (Micah Obiero 68); Jaanai Gordon (Jake Wright 68). Subs (not used): Tom Solanke, Trialist A.
Referee: Aaron Bannister.
Attendance: 942 (227 visitors).
PIC: Russell Dossett.