The Town went down 3-1 to League Two side Cambridge United in the Vertu Trophy Southern Group H tie at the Abbey Stadium.
Mads Andersen gave the Hatters an early lead, but a stunning strike from the excellent U’s midfielder Glenn McConnell and two from Elias Kachunga gave the hosts a deserved win, leaving the Town with one win and a defeat from their opening two matches.
Interim boss Alex Lawless took the reins with the assistance of Paul Benson, Kevin Foley and Kevin Pilkington following Matt Bloomfield’s departure on Monday, and the Under-21 lead coach picked a strong starting line-up with six changes to the side that lost at Stevenage three days earlier.
Hosts Cambridge made 10 changes to their side that beat Crawley on Saturday with former Hatter Pelly Ruddock Mpanzu on the bench for United.
Town had the game’s first attempt on target, with Shayden Morris’ left-footed shot after a quick throw on the right from Nigel Lonwijk, but his effort was saved by U’s keeper Ben Hughes.
The Hatters were enjoying plenty of possession and moving the ball well, and moments after McConnell had shot just wide for the hosts, they produced the move that led to the opening goal on the quarter-hour mark.
Lasse Nordås had seen his effort from Bramall’s left-wing cross deflected over Andersen netting his second goal of the season – and the easiest he’ll ever score – tapping in from close range after Lonwijk had helped Jordan Clark’s deep corner into his path.
Cambridge responded well, James Brophy bursting into the Town box and dragging his shot wide of James Shea’s far post, before Morris beat his man with a nutmeg on the right touchline, got to the byline and crossed for Milli Alli to fire a 20th-minute shot over the bar.
Nordås fashioned a chance for himself just before the half-hour mark, receiving Alli’s flick-on and beating his man only to see his 20-yard shot turned away by Hughes.
Andersen produced a perfectly-timed challenge to deny Kachunga as the United forward pulled the trigger inside the box, before McConnell struck the equaliser on 33 minutes with a curling effort that gave Shea no chance.
Zack Nelson tried his luck from distance a couple of minutes later, shooting straight at Hughes, before Alli headed wide from Lonwijk’s deep cross after more good work by Morris on the right.
It was all square at the break, but Cambridge got their noses in front within 58 seconds of the restart with Kachunga steering in Ben Purrington’s cut-back from six yards out.
The Town tried to hit back, Nordås and Nelson combining to play Alli into the left side of the penalty box, only for his cross-shot to be just too far ahead of Morris and wide of the far post.
United looked likely to extend their lead in the 63rd minute when McConnell raced clear, only to see his effort saved by Shea, with skipper Kal Naismith getting back on the line to divert sub Adam Mayor’s follow-up wide for a corner.
At that point, the biggest cheer of the night was reserved for Hatters legend Mpanzu as the quadruple promotion winner came on as for the hosts, who were soon peppering Shea’s goal again, his fellow sub Kylian Kouassi hitting a deflected shot into the side-netting.
The Hatters tried to mount some pressure and, after a long spell of possession, Yates got to the byline and cut back to eventually create an opening for Fanne to shoot from the edge of the box, but off target.
Cambridge got their deserved third with ten minutes remaining when one long goal-kick forward from goalkeeper Hughes bounced between Mengi and Lonwijk, leaving Kachunga with the freedom of the Abbey to race clear and lift the ball over Shea.
Clark and Fanne fired shot in on Hughes’ goal in the closing stages, but the Town never looked like reducing the deficit and qualification for the next round now depends on a home tie with Brighton Under-21s next in November.
Town: Shea, Lonwijk, Andersen (Fanne 60), Mengi, Bramall (Yates 60), Morris, Naismith, Clark (Gbode 86), Nelson (Richards 60), Alli, Nordas.
Subs not used: Keeley Fox.
Attendance: 1,767, including 591 backing the Hatters