David Ajiboye's eighth minute goal proved too much much to come from as Town suffered a 1-0 defeat at the hands of Sutton.
Ajiboye's early effort nestled into the bottom corner and, despite an improved second half display, Town couldn't break down a resolute visiting defence.
Simon Weaver handed debuts full debuts to Toby Sims, Matty Foulds and Tom Eastman in the three changes from our draw with Stevenage.
Sutton got their rewards for their fast start in the eighth minute when Ajiboye found space just inside the Town area and was able to guide the ball into the bottom corner.
The chances continued to fall the way of the visitors with Louis John heading wide moments before Ajiboye struck the frame of the goal with a powerful effort to end a half of little goalmouth action for Town.
Weaver made no less than four changes at the break in an attempt to rescue the tie, with Matty Daly, Jack Muldoon, Kayne Ramsay and Danny Grant all introduced.
The changes had a positive impact as Town started the half on the front foot, with Armstrong repeatedly finding himself in promising positions.
Two of the half time additions went close to an equaliser after the hour mark with shots from range, Jack Rose doing just about enough to keep out Daly's effort before getting much more of Grant's effort not long after.
Grant again forced Rose into a save, but neither him or his teammates in yellow and black could find a way past the Sutton stopper as Matt Gray's side left with all three points.
Town: Jameson, Mattock (Daly 45), Burrell (Ramsay 45), Thomson (Falkingham 67), Folarin (Grant 45), Sims (Muldoon 45), O'Connor, Pattison, Armstrong, Foulds, Eastman
Subs not used: Oxley, McArdle
Sutton: Rose, Goodliffe, John, Smith, Bugiel (Angol 75), Randall, Eastmond (Beautyman 85), Ajiboye (Boldewijn 67), Kizzi, Milson, WIlson (Dennis 67)
Subs not used:Ward, Hart, Kouassi,
Goals: Ajiboye 8
Referee: A Backhouse
Attendance: 2,356 (141 away)