The Hatters had to settle for a point on their trip to Peterborough as Danny Hylton's opener was cancelled out by a late Jonson Clarke-Harris header for the bottom side.
Manager Nathan Jones made four changes from the team that faced Millwall at Kenilworth Road on Saturday, Fred Onyedinma came into the starting eleven after being on the bench for that 2-2 draw, while Peter Kioso was brought back into the heart of defence with Tom Lockyer missing out through injury.
The additional changes were in the forward roles, with Danny Hylton and Cameron Jerome both brought in to start in place of Henri Lansbury and Harry Cornick respectively, who featured among the substitutes.
The Hatters had James Shea to thank for keeping the scoresheet blank twice in the opening seven minutes, first to produce a brilliant save from Frankie Kent's header, clawing the ball onto the post when it seemed destined for the top corner.
Then, just seconds later, the former AFC Wimbledon keeper got down low to his left to push away a Jack Taylor shot from fully 25 yards, as the hosts came quickly out of the blocks.
Jerome and Adebayo started to make inroads into the Posh backline, the former driving to the byline and drawing a sliding challenge in the box from Ronnie Edwards, although referee Thomas Bramall wouldn't be drawn on Town appeals for a penalty.
Then the Town top scorer skipped on to an Allan Campbell backheel down the left, only to be fouled by Jeando Fuchs, earning the home midfielder the night's first yellow card.
Mpanzu would soon join him for a foul on Jonson Clarke-Harris, before the Hatters' first sight of goal came in the 18th minute, Onyedinma getting to the right byline and arrowing in a lovely cross that found Adebayo's head, but his effort was tipped over the bar by Dai Cornell.
Shea had to push another long-range effort from Taylor round the post, before ex-Hatter Jack Marriott got on the end of a sweeping Posh move in the 25th minute, only to find the Town number one in his way again.
Hylton had a penalty appeal waved away when Josh Knight challenged him in the area, then Jerome had to be replaced due to injury just after the half-hour, Henri Lansbury coming off the bench.
Peterborough had another attempt in the 38th minute when Knight crossed from the right, and although Bree produced a terrific clearing header, Kwame Poku followed up with a shot from the edge of the box that flew just wide.
Campbell soon fashioned a shooting chance at the other end, the ball flying the wrong side of the post after Posh struggled to clear a Naismith free-kick.
Adebayo won an almighty flick-on into Hylton's path on the stroke of half-time, but covering defender Knight managed to get a block on his shot and the scoreline remained goalless at the break.
The Hatters started the second half quickly, Hylton latching onto another Adebayo flick just seconds in and seeing his shot deflected wide for a corner, which Posh struggled to clear with Lansbury eventually attempting a curler that Cornell saved low to his left.
The quick start turned into a perfect start on 49 minutes when Lansbury set Onyedinma racing clear on the right, and his cross found Hylton inside the six-yard box to steer in his fourth goal of the season.
Peterborough mounted a response, with Marriott firing straight at Shea with 52 minutes played, but it was the Hatters who continued to pose the greater threat and were in control.
Poku fired a warning shot, but way too high, before some lovely football down the Town right between Lansbury, Bree and Adebayo led to Peterborough captain Kent being booked for a late, high, scything challenge on Bree on the right byline.
Peterborough survived that free-kick, and another from Bree - this time deeper after Onyedinma had been wiped out in full flow by Ricky Jade-Jones, before the Posh sub spurned a glorious chance with the goal at his mercy with just under quarter-of-an-hour to go.
Jones took Hylton off with ten minutes left, the goalscorer leaving the pitch to a standing ovation from the 3,699 travelling Hatters, and predictable boos from the home fans. Captain Sonny Bradley made his return from injury in his place, racking up his 150th appearance for the club in the process.
The hosts grabbed an equaliser with three minutes remaining, however, when Clarke-Harris met Ward's cross from the right with a far post header that earned Posh a share of the spoils - and it could have been more had Taylor put his header on target and Clarke-Harris' shot not come back off the post in injury-time.
Thankfully for the Hatters, their goal remained intact to the final whistle and they stay fourth in the table ahead of next Monday's trip to Huddersfield.
Scorers:
LT - Hylton 49
PU - Clarke-Harris 87
Att: 10,941