Ollie Price scored the only goal as the youth team drew the season to a close against the Steelmen at RAF College Cranwell.
The result means they finished eighth in the Conference Youth Alliance Midland section.
Boston (4-3-3): Jamie Bradley; Daniel Worthington, Billy Hodgkiss (Joe Cain 46), Ollie Price (Josh Spencer 46), Jordan Sowerby; Aaron Eyett, Jacob Pease, Corey Newman; Leon Squire, Liam Moran (Steven Dovey 46), Joe Pocklington. Sub (not used): Bradley Easey.