Fifty-five minutes into this Rangers romp at Ibrox, Martin O'Neill and Shaun Maloney stood beside each other in the Celtic technical area, chin-stroking, head-scratching, pointing, waving, drowning. To them, in this moment, this Premier Sports Cup quarter-final must have felt like a surreal and nightmarish occasion - and it was only 1-0 at the time.

Rangers had really only started to wreak their havoc. Such was Rangers' dominance, their complete owning of their visitors in every conceivable category, the Celtic managerial brains trust seemed just as lost as every one of their players on the field. Man for man, Rangers won every battle, not for 45 minutes but for the full ninety.

Rangers overwhelm meek Celtic to clinch semi-final spot. No away fans, of course. Not that that had anything to do with it. Being locked out of Ibrox might have seemed like a curse to Celtic folk. In the end, it must have felt like the greatest blessing.

In his early months in the job, Derek McInnes has been looking for a marquee performance. Now he has it. He was looking for a formation that worked and personnel that were big enough and bold enough to execute it and he got that, too. This was 3-0 going on more. Plenty more.

The simplicity of their progression to the semi-final was a touch surreal. Neither of these were in particularly good form coming into this. They were both winning, yes, but they haven't been all that convincing. This season, in their last eight domestic features combined - all won, in fairness - there was only a goal in it at the end in seven of them.

Both sides had got themselves into a cycle of missed chances and, at times, uncomfortable days. So the smart money was on a tight contest. Extra-time, maybe. Penalties? You wouldn't have ruled that out either. O'Neill is such a winning machine that many would have expected Celtic to find a way, somehow. So much for that.

Few Old Firm games surprise you anymore, but this one was a gobsmacker. Rangers had all the intensity and all the togetherness. They had six players making their Old Firm debut from the start but if inexperience can be a challenge in this fixture then it was a challenge they met with gusto.

McInnes and his driven and vastly superior players neutralised Celtic, shut them down, rendered them impotent. Celtic captain Callum McGregor lords it over days like this, but the supreme central midfielder was Dan Neil, not just in his outstanding goals but in the control and the leadership he exerted. With Nico Raskin beside him it was a no-contest in the middle of the pitch. James Penrice did a power of really good work in there, too.

Camilo Duran, playing wide again instead of through the middle, has been one of the players of the season so far, but he hardly existed, totally bossed by Olwethu Makhanya - calm in the maelstrom, classy in nearly everything he did. Kasper Hogh needed a goal having scored in just one game in six - a hat-trick, albeit - but the record signing spent much of his day in Emmanuel Fernandez's pocket. He had no service and no sniff.

Where did this come from? Lord knows, but it makes life very interesting now, not just in the destination of the League Cup - Rangers will be massive favourites against Aberdeen in their semi-final - but in the race for the league title. McInnes might have hit on something substantial.

The big task, of course, is to repeat that energy, that belief, that ruthlessness. You expected Celtic to stir and make a game of it, but they were never allowed to, in part because of their own awful shortcomings with the ball and in other part because Rangers didn't allow them to settle. They hunted them down, right from the opening minutes.

A mood, of sorts, was set as early as the fourth minute when Sam Johnstone, Celtic's jumpy new goalkeeper, passed a clearance straight to Kevin Kelsy, who slashed it wide. Johnstone had been harried by Rangers' press, a big theme of the day. For Kelsy, it was a great chance to strike early, but if he failed then he made amends later on. Kelsy is only in the door, but he looks to have personality and desire.

He was playing with Ryan Naderi, an oft-criticised striker, a player you hear constantly is not Rangers class. Naderi was one of the totems of the day, a work rate that never stopped, a constant menace in hunting and gathering. Naderi might have changed a few Rangers minds on Sunday.

The opener was a microcosm; Naderi robbing Cameron Carter-Vickers, Kelsy then picking out Neil for a sumptuous finish. Rangers were physically and creatively on top, but there's always a feeling that one goal needed to become two to halt Celtic's assumed purple patch, a response that never came. That was the bizarre thing. Total authority for an entire game is a rare enough thing in this contest. Usually there's a spell when the team that's ahead has to weather some kind of storm. Celtic couldn't throw a bucket of water in Rangers' direction not to mind a tempest.

When McInnes' side made it two it was only what they deserved. Penrice put in the cross, Naderi flicked it on and Kelsy banged in the volley. Neil's second and Rangers' third was a peach, a sign of confident uninhibited players enjoying themselves. The smallest of mercies for Celtic was that it stayed at three.

The second part of this drama comes on Sunday, a league game that could not have been better set up had Eddie Hearn been involved in the promotion. Rangers looking to lay down another marker going to Celtic's home, full of 60,000 folk baying for revenge. Given some of the vile songs that were directed at O'Neill at Ibrox then McInnes is in for some treatment. Sadly, he's heard it all over before, as has O'Neill.

McInnes was measured in the aftermath, more low-key than you might have expected and there was sense in that. This was one game and he knew it. They won nothing on the back of it and he knew that, too. Apart from, that is, precious momentum and self-belief and the knowledge of what their standard can be when they get it right. And on Sunday, they got it spectacularly right.