If you were drawing up a list of the day's most improbable forecasts, a landslide Rangers win over Celtic at Ibrox would have ranked somewhere between an unanimous breakthrough on Brexit and an instant solution to global warming.
Unseasonable heat in the dead of winter? Steven Gerrard's team turned up the temperature, that's for sure. Their victory was scalding and wholly deserved. After 10 defeats and two draws in 12 meetings with Brendan Rodgers' team that saw them produce performances that ran the gamut from A for Abysmal to Z for Zzzzz, Rangers finally stirred and gave Celtic a little glimpse of life on the other side.
The Scottish champions turned up at Ibrox for a game of football. Rangers turned up for a battle. If this game was won, ultimately, by a goal from Ryan Jack, its foundations were built on attitude and work-rate and fitness to go like the clappers all day long, on Gerrard devising a perfect game plan that was carried out to the letter by an infinitely hungrier team. Not to mention Rodgers getting his team selection wrong and then it being exposed.
- Rangers' win is about the fans - Gerrard
- Celtic boss Rodgers admits 'best team won'
- Jack goal gives Rangers win over Celtic
- How did the players rate?
'Gerrard needed this, no question'
The hosts hustled and harried Celtic to the point of distraction and disorientation. Dedryck Boyata, Scott Brown, Olivier Ntcham and others will wake up in the night imagining that Jack and Ross McCrorie were in the room with them, tipping them out of their bed. Scott Sinclair, Ryan Christie, James Forrest will think about the last time they were all so ineffective in a game of this kind. That'll take a while. None of Celtic's go-to men in attack were mapped.
Celtic's disintegration was something to see. Every pass - even the simple ones - became an adventure. For a spell, you waited for them to regain their composure and mount an assault down the other end, but you abandoned expectation pretty early in the day. Rangers' intensity was far, far too much for them.
Their only comfort - and it doesn't even amount to a crumb - was that they avoided the kind of outcome that would have been on sale as a DVD come Monday morning. By any reasonable analysis, on the balance of chances created, Rangers were at least three goals better than Celtic at the very minimum. Four would be closer to the mark. Five would not have flattered them.
At the end, the cameras turned to Gerrard in the most significant moment of his brief career in management. Gerrard needed this, no question. After dropping points in nine league games this season - and staring down the barrel of a six-point deficit on a Celtic team with a game in hand - he needed the validation that he was on the right track domestically. That even if Rangers don't win the league, that he shows himself capable of giving Celtic under Rodgers a bloody nose as others have done before him.
Hibernian have done it, Hearts have done it, Kilmarnock have done it, Aberdeen have done it and now Rangers have joined the party at last at the 13th attempt since the Celtic manager hit town. From now until the end of the season, Gerrard can put this victory on the television screen in the team room and say, 'that's your level now, that's what your capable of, that's what we want every week, that's what will make us contenders'.
For Rangers, the thought of beating Celtic is no longer an abstract thing. The win strips away a layer of Celtic's aura. Rodgers' team have now lost four league games in the first half of this season, which is the same number of losses they suffered in the past two league seasons put together. Talking about them being beatable is all well and good, but Rangers don't need to talk about it anymore. They've experienced it.
'Now they need to do it on the road'
The question for Gerrard is about consistency. Can he dig out displays like this on a regular basis going forward? Can he bring to an end soft points getting dropped on the road? Now that he's applying some heat to Rodgers' rear end, can he keep it applied or will a silly draw here and a weak loss there undermine it all?
The winter break is upon us but when they return to league action Rangers have a pocket of games that will tell us much about their durability in what we must now call a title race. Three points separate the top four clubs at the midway stage. How long it lasts is a moot point - Celtic remain hot favourites - but in the here and now there is a chase on for sure.
Those games facing Rangers are Kilmarnock (away), Livingston (away), St Mirren (home) and Aberdeen (away). Their travails have been mostly on the road in the Premiership this season. They've had a flakiness at Livingston, Motherwell and Dundee - where they should be winning - and it has hurt them.
If they leave Rugby Park, the Tony Macaroni Arena and Pittodrie with nine points, they'll have built on what they achieved against Celtic on Saturday and the feeling will harden that, maybe, they are in this for the long haul.
Mr Magoo & Mikael Lustig
There's a transfer window to negotiate in the meantime. Rangers made a £14m loss in their last accounts but the temptation of seeing the whites of Celtic's eyes will surely see them spend again. Gerrard has already spoken about strengthening and his words will only take on greater persuasiveness after what happened at Ibrox. Another option up front is the first priority.
For Celtic, this should come as an awakening. They dozed their way through the summer window and their lack of action contributed heavily to their exit from the Champions League. It's now putting an element of doubt about their domestic dominance.
Mr Magoo can see what they need in the next window - one more striker, possibly two, and a right-back to replace Mikael Lustig. That's the least of it. Rangers exposed Celtic in the heart of the midfield where Brown and Ntcham were thunderously outplayed. That might give Rodgers food for thought also.
He ought to be chastened by what became of his team at Ibrox. The same can be said of Peter Lawwell. The chief executive would never want Celtic to lose to Rangers, but losing so soon after it was reported that he is about to pocket a performance bonus of more than £2m to go with his salary of £1.1m is particularly wounding.
That news will have gone down badly with the faithful, but it's grist to Rodgers' mill as he looks for proper money to reinvent his team. Like Gerrard showing his board the DVD of the game in a bid for new funds, Rodgers can do exactly the same for altogether different reasons.
The Celtic manager hasn't had many poor days in Scotland, but this was the worst of them. There's a little chink in the armoury now. And everyone can see it.