A turbulent afternoon in Govan saw the intense rivalry of the Old Firm reignite with a ferocity that was anything but pleasant.

It’s becoming increasingly clear that reinstating full allocations for away fans is unlikely to happen anytime soon.

The Scottish Cup quarter-final match, lacking in quality play, took a dark turn with unruly crowd behavior, momentarily reminiscent of the notorious 1980 Hampden final riot between the two clubs.

The Scottish Football Association has already initiated an investigation, and it’s quite possible that the Scottish Government will step in, much like they did in 2011 under Alex Salmond following the infamous ‘shame game,’ where Rangers were defeated 1-0 by Celtic in a fifth-round replay.

Compared to the chaos witnessed this time, the earlier incident was almost civil.

The disgraceful scenes started when Celtic fans spilled on to the pitch after their team’s win

An injured steward is carried from the pitch as police struggle to restore order at Ibrox

Fans of both clubs invaded the pitch in scenes that have been condemned by the Scottish FA

Back then, Neil Lennon, serving as Celtic’s manager, was involved in a heated exchange with Rangers’ assistant Ally McCoist, an encounter that dominated headlines and led to a government summit that many deemed unnecessary.

Dunfermline boss Lennon was looking on from the press gantry this time, and, like the rest of us, he must have feared the worst when rival sets of supporters appeared to be on the verge of full-blown physical combat.

This was the 450th Old Firm showdown in major competitions and it proved that the bitter enmity which has both given it a unique status on the sporting stage and disfigured its image far too often remains as deeply entrenched as ever.

Throughout the afternoon, the age-old sectarian anthems rang around Ibrox in a depressing but predictable backdrop to events on the pitch.

Ironically, it was the SFA themselves who forced Rangers’ hand in ending the tit-for-tat restrictions imposed on away fans which began in 2018. Their own competition regulations ensured around 7,500 Celtic supporters were able to pack out the Broomloan Road Stand.

What had been an endurance test for them after 120 minutes dominated by an energetic but toothless Rangers side turned into a wild celebration when substitute Tomas Cvancara slotted home the decisive spot-kick to send Celtic into the last four.

It got a little too wild when some Celtic fans responded to full-back Julian Araujo’s exuberance – the Mexican running to swing on the crossbar in front of them – by spilling on to the field of play.

What started as a trickle of fans became something of a flood which the matchday stewards struggled to contain. At the other end of the ground, the dismay of Rangers fans turned into uncontained fury as scores of them responded by also entering the field of play.

As police reinforcements arrived, pyrotechnics were set off and thrown, along with flagpoles. A mooted attempt to climb the crossbar and bring it down in the style of the Tartan Army at Wembley in 1977 was soon aborted.

Some Celtic players and staff members, including Araujo, unwittingly found themselves in the thick of it and were confronted by Rangers fans who had also come onto the pitch from the enclosure in front of the Main Stand. This was getting seriously ugly.

A line of stewards and police was formed between the supporters, most of whom soon decided that discretion was the better part of their self-perceived valour. The immature youths who form the bulk of the modern ‘ultras’ fan groups went into retreat and slunk back into the stands or out of the ground.

The damage had been done, however, amid scenes unfolding live on TV in front of a horrified national audience.

Celtic’s Green Brigade and Rangers’ Union Bears are often credited with bringing noise and colour to otherwise sanitised environments. On days like this, they are simply a boorishly aggressive presence which Scottish football could happily do without.

Police tried to separate supporters by forming a line between them after the Ibrox quarter-final

The post-match scenes overshadowed an unlikely triumph for Celtic but could do nothing to disguise the paucity in performance levels which has left both them and Rangers so vulnerable this season.

Just as league leaders Hearts were the real beneficiaries seven days earlier when Celtic hit back for a share of the spoils in the Premiership clash here, all of the other Scottish Cup semi-finalists will fancy their chances of going all the way and lifting the famous old trophy at Hampden in May.

There is certainly no fear factor surrounding either of these teams right now. For all that Rangers bossed this game for long spells, having 24 attempts at goal to one solitary effort by Celtic in 120 goalless minutes, they remain wholly unconvincing when it matters most.

Danny Rohl has earned credit for dragging the Ibrox side back into title contention since his arrival in October but question marks remain over the German coach’s ability to get them over the line at the business end of a campaign.

This was a bitterly disappointing exit from the Scottish Cup for Rohl, who also lost out to O’Neill in the semi-finals of the League Cup earlier in the season. Unless he can haul in Hearts’ six-point lead to win the Premiership in the last nine games of the campaign, the jury will remain out on the 36-year-old’s capacity to restore Rangers as a trophy-winning side.

That he was unable to oversee a victory against a Celtic team without the services of key duo Callum McGregor and Kieran Tierney is another blot on Rohl’s copybook.

By contrast, O’Neill’s Midas touch with this unremarkable but gritty Celtic side is still intact and he remains in contention for a domestic double.

Rangers’ visit to Celtic Park after the split may yet decide which of them, if any, can reel in Hearts. Quite how many Rangers fans will be there to see it remains to be seen.

This fixture continues to provide drama and intensity of a level few other match-ups around the football globe can emulate.

Unfortunately, the same remains true of the festering hatred nursed by so many of their followers, which left us so close to witnessing truly calamitous scenes here.