The Pilgrims were 3-1 victors over a strong Mickleover Sports side, who had equalised during the first half through Fin Barker.
Millar opened the scoring on six minutes and captain Owen Sheriff restored United's lead three minutes before half-time - following Barker's 35th minute leveller. Millar capped a fine individual display with the game's clinching goal nine minutes from time.
Boston (3-4-2-1): Charlie Wilkinson; Bailey Dilley, Owen Sheriff, Ben Robson; Krisztian Gagyi (Charlie Earth 66), Mackenzie Burdass, Joe Melson, Zane Millar; Han Stevens (Jake Henderson 85), Elliot Foster; Sam Harris (Logan Tate 83). Subs (not used): Taylor Jaine, Ishaan Sumal, Finley Rodgers, Cameron Fox (gk).
Referee: Andrew Wilson.
Attendance: 404.
PIC: Russell Dossett.