In an all-too familiar sight for the Lilywhites faithful, their team faced a one-goal deficit at the Tottenham Hotspur Stadium when Tahith Chong struck early doors, as Spurs failed to score in the first half of a Premier League home game for the seventh time in a row.
However, Issa Kabore offered the hosts a helping hand with an own goal early in the second half, before Son Heung-min's 86th-minute strike completed the hosts' turnaround and sent them into the Champions League places ahead of Aston Villa's clash with Wolverhampton Wanderers in the evening slot.
Despite the return of Micky van de Ven from a hamstring injury, the Dutchman was only considered for a spot on the bench, where Richarlison joined him amid careful management of his knee injury.
Timo Werner for Brennan Johnson was the solitary change on the Lilywhites' end, but it was the away end who would be sent into unexpected pandemonium with just three minutes on the clock, thanks in no small part to a former Lilywhites attacker.
Andros Townsend beat Yves Bissouma far too easily down the right and crossed for an unmarked Ross Barkley, who in turn shifted the ball out to the left for Chong to pick out the far corner with a brilliant low drive.
Electric Johnson sparks Tottenham turnaround
As well-worked as Luton's opener was, Spurs defensive shape was all over the place, as was Werner's finishing in the 15th minute as the RB Leipzig loanee tried to emulate Chong's left-footed strike across goal but fired wide.
The German's frustrations continued during a chaotic few seconds in the 19th minute, where Son witnessed his strike agonisingly hit both posts before Werner and Pape Sarr were thwarted by Hatters defenders in the bedlam that ensued.
Spurs' failure to equalise before the break made it six straight first halves in which the Lilywhites had not made the net ripple, and Ange Postecoglou's men departed with their heads down to a chorus of boos from the vexed home faithful.
Dejan Kulusevski - culpable for the Luton opener - was sacrificed at the break for Johnson as Postecoglou desperately sought solutions to Spurs' lack of bite, and the Australian's decision was vindicated just six minutes after the restart.
Johnson and Pedro Porro combined with a slick one-two down the right before the former delivered a ball across goal intended for Werner, but Kabore - under pressure from the German - inadvertently fired the ball past a helpless Thomas Kaminski to draw Spurs level.
With their tails up, the rejuvenated hosts instantly went in search of a second, which nearly arrived through Son in the 56th minute, only for Kaminski to deny the Tottenham captain with his legs.
Luton drop below dotted line
Guglielmo Vicario was still being kept busy at the other end, though - tipping a sensational Jordan Clark shot round the post in the 64th minute - but the hosts were a matter of millimetres away from taking the lead in the 78th minute.
After Johnson drilled a low strike into Kaminski's body, the ball would seemingly trickle over the line, but Alfie Doughty produced a spectacular last-ditch clearance, and there was no buzz from Jarred Gillett's watch in what was one of the tightest goal-line calls the Premier League has seen.
However, no special technology was needed to confirm Tottenham's merited second in the 86th minute, as Postecoglou's men turned defence into attack in a flash and finally took the lead as Son's strike deceived Kaminski via a deflection off of Daiki Hashioka.
While Postecoglou's side will spend at least two hours in the top four thanks to their superior goals scored over Villa, Rob Edwards's men have dropped back into the relegation zone in 18th place, below Nottingham Forest on goal difference thanks to the Tricky Trees' draw with Crystal Palace.
Tottenham's first fixture of April sees the Lilywhites head to West Ham United for next Tuesday's capital derby, one day before Luton make their second trip to North London in a row to face Arsenal.