Andy Awford’s Fratton Park reunion ended in frustration for Pompey as the home side failed to find a way past the Hatters.
Some 260 days after leaving as Blues manager, he was back in the Frogmore Road dugout, having recently taken over as caretaker from John Still.
And the 43-year-old steered his current employers to a goalless draw in a whole-hearted, if toothless, showing against Paul Cook’s men.
Of the sides, the hosts were the better and looked considerably more of a threat – with visiting goalkeeper Mark Tyler, in particular, busy during the opening 45 minutes.
Luton mustered just the one shot on target, while they failed to win a single corner during the duration of the match.
That was in contrast to the Blues’ 10.
Yet Pompey could find no way through a well-organised opposition as the second half petered out into a case of honours even in a match which became a rather flat affair.
For Cook’s side, makeshift central-defender Adam Barton did superbly, but it was at the other end of the pitch where they didn’t quite fire as they failed to break down the Hatters.
Delight then for Awford, who departed Fratton Park in April following the end of an unsuccessful spell as manager.
Regardless, he unquestionably remains a popular figure at Pompey – in recognition of his playing days and then spell as caretaker boss which kept the club in the Football League.
At the final whistle there were hugs delivered by Awford for Conor Chaplin and Barry Harris, followed by applause which was directed towards the home crowd of 17,668.
It remains to be seen whether he takes over permanently at Luton, yet his team put in a solid performance to blunt the Blues.
With Adam Webster suspended for one game following his straight red card at Leyton Orient on Boxing Day, Barton was handed a start as a stand-in central defender alongside Matt Clarke.
It was a case of needs must for Cook, with Christian Burgess out with an ankle ligament injury and Jack Whatmough deemed not ready to feature following his lengthy lay-off.
Barton had previously lined-up against Exeter in the Johnstone’s Paint Trophy in the unfamiliar role, while he came off the bench to fill in during Saturday’s 3-2 loss at the O’s.
That was the only change from the side which had to play for 67 minutes with 10 men at Brisbane Road.
Replacing Barton on the bench was Jayden Stockley.
He was handed a rare squad place, with the Bournemouth striker’s loan spell set to expire early next month.
However, once again there was no Nigel Atangana in Cook’s match-day 18 as his Pompey future grows ever more in doubt.
The Blues had a scare in only the third minute, when Stephen O’Donnell crossed from the right and Ryan Hall’s fiercely-struck volley flashed past the post.
If it had been on target, keeper Brian Murphy would have been helpless to deal with the Hatters’ early opportunity.
The hosts responded with Enda Stevens breaking down the left and slipping a pass across to Marc McNulty, who fired an angled attempt well over the bar.
On 17 minutes Caolan Lavery chased on to a long ball down the middle and outmanoeuvred central-defender Scott Cuthbert to open up a glimpse of goal.
Yet the striker’s subsequent right-foot shot deflected off O’Donnell and looped over for a corner, which came to nothing.
Hatters keeper Tyler was then drawn into his first save, when he finger-tipped away McNulty’s angled drive from the right following Gareth Evans’ pass.
In the 26th minute Stevens came across to clear ahead of Josh McQuoid from almost on his own goalline, after Barton had accidentally stabbed the ball across as he challenged Jack Marriott.
Then, at the other end, McNulty was agonisingly short of making a far-post connection to Stevens’ cross from the left which was driven into the six-yard box.
Tyler was drawn into a double save on 37 minutes when, firstly, he flung himself to his left to beat out Kyle Bennett’s shot, then he stopped McNulty’s far-post attempt in the follow-up.
The lively Bennett then won a free-kick after being chopped down by Alex Lawless, who was booked for his part.
However, Ben Davies’ dead-ball hit the side-netting.
Although, the confused match-day announcer did announce it as a goal – much to the amusement of Cook and everyone else at Fratton Park!
As half-time approached, the Blues forced a string of corners from the right, one of which saw Bennett’s goalbound header blocked as the home pressure continued.
Goalless at the break, five minutes after the restart Michael Doyle produced a diving header at the near post to send Davies’ right-wing corner over the bar.
On 58 minutes, another Davies corner was met by a Clarke header, but Tyler easily plucked it from underneath his crossbar.
Gary Roberts was introduced in the 64th minute for Lavery, with McNulty pushed further forward as the lone striker in the search for the breakthrough.
It wouldn’t be until the 71st minute, though, that Luton had their first real attempt on goal.
Former Fratton Park striker Paul Benson slipped in substitute Craig Mackail-Smith, whose curling right-foot shot was taken by Murphy.
Yet it would be Pompey who threatened most, and during five minutes of time added on Clarke somehow headed wide from six-yards out after Davies had volleyed in a cross from the right.
There was to be no way through, however, and the match finished in a goalless draw to at least bring a smile to the returning Awford’s face.