If ever a stadium can be rocked by silence, this was the moment. With no visiting fans allowed at any of this season’s Glasgow derbies, Ryan Naderi’s winning goal was met with nothing but the banging of fists of the clear plastic of the Rangers bench and the shouting of the broadcast commentators. A screaming void of apathy and atrophy, the sound of a beckoning abyss, of three straight Celtic defeats and a title race blowing open.

In the coming three weeks, as club football dissolves for the international break, noises and voices will pour into the void: some helpful and some not. This, of course, is a familiar feeling for any club of Celtic’s size, and naturally the temptation will be to block out the noise, stay the course. This would be a grave mistake. If last season’s double illustrated the way this club can still rise above adversity, there can no longer be any hiding place, no equivocation with the alarming drop in standards that was evident here.

Naderi’s goal, bundled in from close range after Kim Min-su’s long-range effort was parried helpfully into his path by Viljami Sinisalo, was simply the most consequential emblem of Rangers’ superiority here. Derek McInnes arrived with an unchanged team, coherent patterns of play, a functional and hungry midfield, order to their chaos. None of this has been remotely visible at Celtic for a while.

Even as they desperately chased the game in the final minutes, they could barely fashion a chance, barely get hold of the ball. Martin O’Neill sprang a surprise with Luke McCowan in midfield, discarded his back five at half-time and rolled through his substitutions, but no plan ever really emerged from the fog. Celtic are basically like the tangled ball of printer cables and headphone wires in the bottom drawer: try as you might to unpick them, you’re never quite sure whether you’re untangling the threads or simply making them tighter.

And so, time to face some awkward questions. Is Callum McGregor, club legend, still fit for purpose? McGregor is 33 and the captain, but has looked desperately off the pace for some time now. Does Liam Scales need replacing? Does Kieran Tierney still have the legs? Are either of their goalkeepers actually any good? Does O’Neill have the expertise to steer them out of trouble? And would you trust this board, still essentially hollow of footballing expertise, to oversee the required changes?

The chaotic end to the transfer window and the calamitous European exit to Lask offer an illusion of urgency, but really this is a squad that has needed refreshment for years. Yet few of the big summer signings looked equipped for a game of this magnitude. Kasper Høgh was only introduced at half-time and offered little. Camilo Durán gave Emmanuel Fernandez a rough ride early on before disappearing from view. Mika Baur looked overawed, overrun by a Rangers midfield superior not just in numbers but in purpose.

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Roundup: Vrancken bewildered by VAR as Hearts frustrated at Kilmarnock

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Wouter Vrancken was left bewildered by the “strange” video assistant referee decision to rule out an early Hearts goal in their 1-1 draw at bottom-placed Kilmarnock. The Jambos thought they had gone ahead in the 11th minute when Laurent Mendy’s effort – which appeared to be going wide – was diverted into the net by the Killie defender Cathal McCarthy. But the VAR, Matthew MacDermid, advised Duncan Nicolson to rule it out as the ball had accidentally struck Mendy’s hand. Killie went ahead a few minutes later through a Jamie McCart own goal before Stephen Kingsley equalised in the 86th minute (pictured).

But Vrancken cited similarities with the recent incident involving Manchester United’s Harry Maguire against Ipswich and felt Mendy’s inadvertent handball should have been rendered irrelevant by McCarthy heading the ball into the net. “For me, when it’s such a clear situation, it’s strange that the VAR comes in between and rules wrong,” said the Belgian. “We had a meeting last week about the laws of the game and the refs did their explanation but when you don’t see them applied in the game, then I’m thinking this is strange."

Martin Boyle ended Hibernian’s losing streak at home after they fought back to claim a point in a 1-1 draw against Aberdeen. The Dons went ahead in the 17th minute with a composed finish from former Hibs striker Kevin Nisbet. Managerless Hibs – with John Potter in interim charge after David Gray’s midweek sacking – looked bereft of confidence for long spells. However, the Leith side – who had lost six successive games at Easter Road – earned a share of the spoils when Boyle levelled from the penalty spot in the 62nd minute after Jack Milne dragged Jason Kerr to the ground.

Steven Pressley praised Joe Westley for the bravery he showed by playing in Dundee's 2-1 home win over Motherwell. The former Burnley striker fractured his cheekbone against Hearts a fortnight ago but declared himself available after deciding against having surgery. Instead, he played wearing a protective mask and nett Dundee’s opening goal from the penalty spot before Bradley Fink doubled their advantage. Alex Lowry pulled one back for the visitors just before the break but the home side held on.

Pressley said: “Joe showed great courage. But he gave a wonderful performance, without any trepidation. Joe was fearless in everything he did and to score a goal is really important for him because he lives off them."

Jim Goodwin hailed his side’s performance as the perfect tonic as Dundee United defeated St Mirren 3-0 in a one-sided contest in Paisley, with first-half goals from Jesse Randall, Lyall Cameron and Kevin Ciubotaru. It was Goodwin’s first appearance in the dugout since a recent health scare and the United manager said: “On a personal note, it was great to be back. Certainly the best medicine that I could have hoped for was that type of result and performance."

A stunning set-piece strike from Enes Alic in the sixth minute of stoppage time secured a dramatic 1-1 draw for 10-man St Johnstone against Falkirk. Falkirk took advantage of Cheick Diabaté’s 54th-minute red card to seize the lead through Ethan Ross on the hour. But Alic found the top corner from 25 yards to move Simo Valakari’s side up to sixth place. Press Association

Photograph: Mark Runnacles/Shutterstock Editorial

James Penrice, on his way to club-legend status after just nine games, was again the beating heart of this derby, its unstable element, its unreliable narrator: the left-back underlapping through the centre, popping up in the box, putting a header just wide. Alongside him Dan Neill and Nicolas Raskin are already forging a formidable partnership in the centre. Naderi and Kim created havoc in the attacking areas. McInnes’s team are by no means the finished article but in their biggest test of the season they showed unity and spirit, the deceptively tough gig of repeatable skills under the highest pressure.

That they were unable to celebrate this triumph with fans in the stadium was a source of lament, and a measure of just how ugly this fixture has become. And of course this is a failure not just of the two fanbases but the authorities who have allowed the ugliness to fester, who have talked a tough game on sectarianism but done little in practice to combat it at source. Over the years Celtic v Rangers has become the sort of fixture that is no longer relished but dreaded. But it is of course Celtic who will wake with the heavier heads on Monday morning.