The Pilgrims gunned down Bishop's Stortford at Boston Town's DWB Stadium in their latest Football Conference Youth Alliance fixture.
It completed a good week for United, following a 3-0 win over AFC Sudbury Reds on Monday.
Boston (3-5-2): Travis Portas (Harry Payne 65); Kofi Ross, Daniel Moulds, Elliot Andrew; James Gordon, Jack Dykes, Harry Vince, Oli Drummond, Bailey Forth (Liam Mead 65); Kemal Yenibertiz (Jack McCallum 50), Tinashe Chavundura.