The Pilgrims secured National League U19 Alliance Academy Division North spoils at the Jakemans Community Stadium.
Henderson opened the scoring midway through the first half - with top scorer Horne sealing the deal after the break.
Boston: Cameron Fox, Ellis Perry-Burdett, Josh Doran, Will Langford, Finley Ging, Charlie Brooks, Jake Henderson (Oliver Fields 80), Kris Zaluzinskis, Nathan Bowen, Joe Wilkinson (Rueben Fogg 70), Luke Horne. Subs (not used): Flynn Slater, Daniel Martin (gk).
Referee: Ian Ruddock.