From a vantage point high in the main stand, the Celtic directors watched silently as the tense match drew to a close. But beneath their calm exterior, it was hard to imagine they weren’t all wrestling with the same troubling concern.

In a title race as taut as a piano wire, the question looms: how significant will the twelve points lost during Wilfried Nancy’s tumultuous tenure prove to be for Celtic’s championship aspirations?

During his initial interim period, Martin O’Neill led the team to five straight league victories. This narrow triumph over Falkirk extends the Northern Irishman’s flawless run to seven matches. It’s hard to imagine where Celtic would stand without O’Neill’s willingness to step in and steer the ship twice this season.

If the team falls short in the end, O’Neill won’t be the one to blame. The responsibility will rest with those who approved the ill-fated hiring of the hapless Frenchman.

Despite eking out a victory thanks to Benjamin Nygren’s header just before halftime, the performance lacked brilliance.

Martin O’Neill has plenty to ponder as his side look to keep pace in the title race

Benjamin Nygren won the ball in amongst a congested box to head Celtic in front

Benjamin Nygren’s first-half goal proved crucial as Celtic took all three points

While the team’s shortcomings in attack are apparent, that’s only part of the problem. The squad is in dire need of revitalization across the field.

Unless that’s addressed in short order, the remainder of this campaign will be one almighty struggle.

It was a victory which owed everything to endeavour and character from the visiting players. Frankly, under Nancy, it was a game they probably would not have won. O’Neill has brought steel and a winning mentality back. It can take you a long way in this game.

Falkirk may feel they ought to have come away with something tangible for their considerable efforts. It was their misfortune to find Kasper Schmeichel, once of this parish, back on fine form.

The man who was in the Falkirk team the last time they beat Celtic in 2007 pulled off a string of saves, the best of which came when he denied substitute Ethan Williams near the end.

While John McGlynn’s side lost for just the second time in five outings, they won’t be too discouraged by this. They’ll take comfort from knowing that Celtic were truly never comfortable. They gave it everything.

O’Neill’s claim on Tuesday that the lack of signings was ‘down to me’ was a nice line, but no one really bought it. The issues were apparent long before he walked in the door.

Fourteen days after the window opened, Celtic took the field for the third time this year looking distinctly threadbare.

Daizen Maeda was again asked to play through the middle with Hyun-jun Yang and Seb Tounekti tasked with providing the width. Nygren displaced Reo Hatate.

For 10 minutes, O’Neill’s side threatened to pick off where they left off against Dundee United. Playing with tempo and pressing in unison, they dominated the early exchanges.

Yang dragged a shot wide of the far post with Maeda sending a looping header onto the roof of the net.

Falkirk then got with the pace of the game. Barney Stewart tested Schmeichel with a low strike after Callum McGregor was sold short with a pass.

McGlynn’s side were increasingly brave on the ball and patient in their build-up. O’Neill and Shaun Maloney had plenty to ponder as they whispered in each other’s ears on the sidelines.

The visitors started to get sloppy. Yang, who’d initially asked plenty questions of Leon McCann, began turning the ball over cheaply. The same applied to Auston Trusty who was relieved to see a senseless free-kick he conceded amount to nothing.

Filip Lissah had also begun to get the measure of Tounekti. The full-back advanced and sent a fizzing strike into Schmeichel’s arms.

The Bairns’ best opening was a spectacular solo attempt from Kyrell Wilson. Turning inside Kieran Tierney, he simply ran and ran. He dropped a shoulder then took the ball around the keeper. Just as he prepared to pull the trigger, though, his balance went and the ball ended up in the stand.

It encouraged Falkirk. Slackness from Maeda saw Stewart given a look at the target. Schmeichel again delivered with a solid stop.

When another Celtic attack broke down, McCann advanced up the field and steered a shot just beyond the far post.

Although Maeda’s header from a corner forced Scott Bain into a smart stop, Celtic’s play was becoming disjointed as the half-time whistle neared.

Coming a minute from the whistle, it was an awful goal for the Bairns to concede. Engels’ corner fell on the six-yard box like a bomb dropping out of the night sky.

Falkirk boss John McGlynn was left to rue the chances his side missed against Celtic

Amid the congestion, Nygren got his head on the ball and flashed it home for his 12th goal of the season.

There was one personnel change at the break, but it didn’t involve either team. Sean Murdoch, who started as fourth official, took the whistle from John Beaton, presumably on account of a muscular injury.

The scoreline wouldn’t have prevented O’Neill from imparting some harsh truths in the dressing room.

His side re-emerged with a greater sense of purpose. Tounekti floated one effort just wide.

The game became stretched. On more than one occasion, Trusty’s pace came to Celtic’s rescue as Falkirk broke in numbers.

McGlynn gambled early with the twin introduction of Ben Parkinson and Louie Marsh. O’Neill replaced his wingers with Hatate and Luke McCowan.

While Celtic were markedly better after the turnaround, they still couldn’t find the killer pass.

Falkirk began to huff and puff, the order and composure they’d shown earlier on in the game becoming lost in the blizzard of replacements.

The big chance they craved fell the way of substitute Williams. Schmeichel did brilliantly to stretch out a leg.

Johnny Kenny will feel he should have doubled Celtic’s lead late as Liam Henderson stooped to block.

They didn’t need it in the end. What’s as clear as day, though, is that O’Neill badly needs fresh faces.