For only the third time in 15 seasons, the United youngsters exited at the first hurdle, following a 1-1 draw after extra-time.
Jenson Bark had cancelled out Sam Bacon’s opener for the hosts, but Marshall Young and Harrison Holland were denied at either end of the shootout to hand Mickleover a 4-3 win on spot-kicks. Lewis Bontoft, Xander Crashley and Nathan Stevens successfully converted for the Pilgrims.
Boston (3-5-2): Seth Greeves; Jamie Gaukroger (Nathan Stevens 91), Harry Cranfield, Daniel Fisher (Mikey Adegboyega 117); Xander Crashley, Taylor Gray (Sam Hughes 104), Marshall Young, Lewis Bontoft, Will Jackson; Jenson Bark, Harrison Holland. Subs (not used): Dylan Mercer, Cole Willerton.