Fielding a mix of senior and youth team players, the Hatters took an early lead when first-year scholar Casey Pettit raced onto a Josh Boorn through ball and lobbed onrushing Biggleswade keeper Sam Donkin.
A host of chances went begging as the first half progressed, but Lloyd Jones – by this time wearing the captain’s armband after Alan Sheehan went off at half-time – doubled the advantage with just under 20 minutes to go with a thumping header from a Jake Jervis corner.
Biggleswade staged a comeback, however, with two goals in as many minutes from Kieran Forbes (75) and Calum Stead (76) bringing them level.
In the penalty shoot-out that followed, Jones, Brendan Galloway, Avan Jones and Jervis all netted for the Town, with James Shea saving twice to secure a 4-2 victory.
TOWN XI: Shea, Neufville, Jones, Sheehan (Panter 46), Galloway, Beckwith, Pettit (A Jones 69), Nicolson, Boorn (Wilson 81), Jervis, Trialist. Subs: Stevens, Halsey, Moloney, Parker
Goals: Pettit 4, L Jones 72