The Pilgrims proved too strong for West Bridgford in the preliminary round encounter played behind-closed-doors at Nottingham Forest's Nigel Doughty Academy - three weeks after the original tie had been abandoned due to the tragic collapse and subsequent passing of Dylan Rich.
Harris scored after 43 seconds and then again in the 61st and 76th minutes to render Jack Wynne's 64th minute effort for the home side as nothing more than a consolation.
Boston (3-4-2-1): Charlie Wilkinson; Bailey Dilley, Owen Sheriff, Ben Robson; Krisztian Gagyi (Jake Henderson 80), Joe Melson, Mackenzie Burdass, Zane Millar (Logan Tate 65); Elliot Foster (Charlie Earth 70), Han Stevens; Sam Harris. Subs (not used): Taylor Jaine, Finley Rodgers, Ishaan Sumal, Cameron Fox (gk).
Referee: Martyn Fryer.
Attendance: Behind-Closed-Doors.