The Hatters’ bid for their second successive Third Round appearance in the FA Cup was shattered by a 2-0 defeat away at League One outfit Peterborough.
Conor Washington’s first half strike had Posh ahead at the break before substitute Marcus Maddison sealed the Town’s exit just eight minutes from time.
Craig Mackail-Smith had hit the post on his return to London Road, Peterborough’s quality proved decisive in East Anglia.
Mark Tyler delivered a stellar performance against his old side, producing a string of saves to keep the Town in the contest despite Peterborough’s heavy shot count.
John Still opted for five changes from last week’s 3-0 defeat at Newport, drafting in Mackail-Smith and Paddy McCourt, while Sean Long, Marcus Okuonghae and Nathan Doyle – who captained in Scott Cuthbert’s absence – also started.
The Hatters began the first half on the back foot and perhaps should have been a goal down when Lee Angol spun Luke Wilkinson on the six-yard box before firing wide.
The Posh had an even better chance just a minute later when Harry Beautyman, on for the injured Jermaine Anderson, missed the target from three yards under pressure from Tyler, who was returning to his former ground after playing almost 500 games for the hosts.
The Hatters keeper was required again to thwart Conor Washington, who could have had a first-half hat-trick, blocking two close efforts after Angol had played him in from an excellent Michael Bostwick cross-field ball.
The visitors got their foothold midway through the half, with Jonathan Smith taking aim from 25 yards only for the effort to be deflected out for a corner.
It was from a corner where the Hatters proved troublesome on the 27th minute when Luke Wilkinson, who seemed to be tugged by a home defender, got a free run on his man but could only nod McCourt’s delivery over the bar when unmarked, eight yards out.
The Town were enjoying their best period of the first half, and good work from Alex Lawless and Olly Lee down the left saw the latter swivel on the edge of the area, but his shot was saved by Ben Alnwick, required too infrequently from a Luton perspective.
But the next attack saw Peterborough take the lead. Callum Elder and Washington linked up down the left flank, with the latter taking the ball into the area before jinking inside and out of Okuonghae and firing to the far post past a helpless Tyler.
Despite being a goal down, the Hatters were far from down and out in the first period, and came the width of the post away from equalising in the closing stages.
Excellent battling from McCourt and Lee saw the ball pinched back, with the latter releasing McQuoid to set up a three-on-two. McQuoid unselfishly laid it off to Mackail-Smith, but his 15-yard strike smashed the woodwork and kept the Town behind going to the break.
The hosts began the second half in a similar vain to the first, using their divisional advantage to knock the ball around with comfort, and almost doubled their advantage when Angol launched a fierce shot which Tyler did well to keep out.
Still the Posh remained a threat. Substitute Miles Addison was the latest to test Tyler with a long-range effort, while Washington had a glorious opportunity to net his second, beating the Hatters offside trap from an Oztumer reverse pass, cutting an effort right across the face of goal where Beautyman was inches away from converting.
The home side wasted yet another opportunity as Angol could only head wide from a central position twice in the space of five minutes, while John Still opted for a change in system with Cameron McGeehan and Danny Green coming on in place of Lee and McCourt.
The Posh, who notched 35 shots in the game, were showing why they are the top scorers across the top four tiers, but with just one goal separating the two sides, a moment of magic could bring the Town level in the cup tie.
And it almost came, too. Good hold-up play from Mackail-Smith saw him release Smith down the right, and with plenty looking for service in the area, Smith laid the ball into empty space and the chance was averted.
The ex-Posh keeper was a big factor in keeping the Hatters in the contest, tipping over a left-wing Elder cross that had looped off Lawless and was creeping under the crossbar until the right-hand intervention.
But there was nothing he could do to stop Maddison’s striking into the bottom corner. After a period of Hatters pressure, the substitute took advantage of space down the Hatters’ right, cutting inside to double the lead in the final ten minutes.
The Town battled to the final whistle, but were knocked out of the FA Cup at the second round stage for the second time in three years, losing their third successive game in all competitions.
Town: Tyler, Long, Lawless (sub Griffiths 77), Wilkinson, Okuonghae, Smith, Doyle, Lee (sub McGeehan 61), McCourt (sub Green 72), McQuoid, Mackail-Smith.
Unused subs: Justham, Hall, Guttridge, Williams
Attendance: 8,379, with 1,740 backing the Hatters.