It may go down in history as the first Old Firm derby to be won and lost from the substitutes’ bench.
But on a day when energy levels were being stretched to the limit of exhaustion – and maybe even beyond – the kitchen sink that Giovanni van Bronckhorst was able to throw onto the pitch at Hampden amounted to much more than Celtic were able to cope with.
In Scott Wright, Scott Arfield, Steven Davis, Glen Kamara, Leon Balogun and Fashion Sakala, the Dutchman was able to refill the tank just when it seemed impossible for Rangers to keep on moving after the marathon they put themselves through against Braga on Thursday night.
The fact of the matter is, while all six of them made huge contributions to a Scottish Cup classic, too many of Celtic’s players forgot to turn up for their work.
Ange Postecoglou also made six changes to his starting line-up over the course of 120 minutes of a compelling, pulsating semi final.
But although Kyogo Furuhashi, Matt O’Riley, Tony Ralston, James Forrest, Stephen Welsh and David Turnbull were all given a chance to make an impact, none of them managed to lift the level of what was a flat and uninspired Celtic performance.
Yes, it did look at one point during the second half as though Celtic might win this one even despite their own sloppiness.
How they made it to half-time with Joe Hart’s goal still intact was something of a mystery, given that Rangers had spent the first 45 minutes playing them off the pitch.
In fact, in the opening seconds James Tavernier set the tone for the match when he almost effortlessly muscled Jota off the ball down near his own corner flag and from that moment, Rangers were sharper, stronger and hungrier in just about every area of the park.
This must surely have set the alarm bells ringing for Postecoglou, especially given the energy-sapping drama which pushed Rangers to the limits less than four days earlier.
It made no sense at all for them to be bursting out of the traps like this and forcing his players so far onto the back foot.
But that’s exactly what was happening and especially in the midfield where the outstanding John Lundstram seemed to be taking on all comers all by himself.
In fact, Lundstram’s performance almost defied belief.
That the Scouser lasted 101 minutes before being replaced by Kamara was a freakish phenomenon all on its own.
But, while he was dominating the middle of the pitch during that first half, Celtic’s players looked strangely overwhelmed by it all.
So much so, as a matter of fact, that it was hard to understand why Postecoglou waited for what seemed like an eternity before turning to his own bench and searching for alternative solutions.
Just the sight of Kyogo seemed to spark the Celtic supporters into excitement and even though the Japanese talisman failed to get up to anywhere near top speed, within six minutes of his arrival they had opened the scoring and planted one foot in the final.
With the wind knocked out of their sails it did look at that stage as if Rangers might have chosen precisely the wrong time to rediscover an
inferiority complex. All at once, the belief appeared to be draining from them, even if the energy levels had not yet begun to run out.
From the moment Greg Taylor’s shot brushed off Calvin Bassey’s studs and nestled into the bottom corner of Jon McLaughlin’s net, it did seem as if this might be one savage blow too many for Van Bronckhorst and his players to withstand.
And had Cameron Carter-Vickers not smashed the biggest chance of the match onto the face of McLaughlin’s crossbar after a wobbling Rangers had failed to deal with a corner kick then, yes, there would most probably have been no way back.
But it was around this point in the contest when Van Bronckhorst opted to make some hugely testing and significant decisions of his own.
Having had no choice but to replace the hobbling Aaron Ramsey with Wright in the first half, the Rangers boss had to be bold enough to take off a mainstay in Ryan Jack and a potential match winner in Joe Aribo and send fresh legs onto the battlefield.
By sending on Arfield and Davis he succeeded in turning this tie on its head.
Within three minutes Arfield had swept home an equaliser and with Davis providing composure and game management in the middle of the pitch, Rangers suddenly reclaimed control of a contest which had seemed to be getting away from them.
The final, decisive plot twist came when Borna Barisic felt his hamstring nearing breaking point and waved towards his manager in distress.
Van Bronckhorst reacted by sending on Balogun, shifting Bassey to left-back and also replacing the exhausted Kemar Roofe with Sakala’s searing pace.
Those changes were made in minute 107. And within seven minutes Bassey had bombed in behind the Celtic defence to fire a cross into Sakala’s path.
That the striker didn’t actually touch it was neither here nor there.
The darting run alone was enough to spook Carl Starfelt into jabbing out a boot and sending the ball into the back of his own net.
That this Celtic side offered nothing in response was another indictment of a lethargic performance from start to finish.
It is Rangers who will now go on from here to face Hearts in the final while also eyeing up a run all the way to Seville in the Europa League.
Yesterday’s performance proved they have the desire, drive and energy to go the distance.
They also have a manager who is capable of squeezing every last ounce out of a squad which has been built with such ambitions in mind.
