That pettiness is a constant in the Glasgow football scene was exemplified by the stadium announcer at Celtic Park, who staunchly refused to use the word “Rangers” during the first Old Firm clash of the season. It was “the visitors” who made substitutions. Don’t mention the R-word.

Neither of these clubs are particularly good at playing the adult in the room. In the case of Celtic, one wonders why on earth they bother. All this fixture did was demonstrate the chasm that exists between teams who cannot appropriately be described as rivals. A 3-0 win undersold the hosts’ level of domination. As preposterous as it sounds at the start of September, the Scottish Premiership will be retained by Brendan Rodgers with minimal hassle. Had the Rangers players instead donned the shirts of Ross County, this game would have been no different whatsoever in appearance.

Rodgers started this game with more than £20m worth of summer signings and a Barcelona loanee among his substitutes. Whether fuelled by competition for places or otherwise, Celtic were considerably sharper than their visitors. The gulf in class between Celtic and Rangers is glaringly obvious but there was little excuse for the timid display from those in blue. Rangers’ attitude was defeatist. The strongest praise for what Celtic produced is that Matt O’Riley, sold to Brighton before the window closed, was not missed at all.

In his post-match assessment the Rangers manager, Philippe Clement, clung pretty unconvincingly to possession and shot statistics. The Belgian praised his side’s first 10 minutes, during which Cyriel Dessers spurned a chance – he had been flagged offside anyway – and Rabbi Matondo headed wide of goal. Thereafter, Celtic simply took control. It feels damaging in respect of Clement’s reputation among his club’s support that he has now faced Celtic five times and is yet to win. Clement called for patience with his newly assembled squad, which is unlikely to fly among an edgy fanbase.

Daizen Maeda opened the scoring after the outstanding Paulo Bernardo fed Alistair Johnston, whose cutback reached the Japanese forward. In an all-too familiar scene for Rangers, James Tavernier allowed Maeda to reach the ball before he did. Tavernier’s defensive failings are a regular feature of this derby.

Reo Hatate provided a candidate for miss of the season before Kyogo Furuhashi spared his teammate’s blushes. The forward collected Greg Taylor’s pass before blasting past Jack Butland from 25 yards. The doubling of Celtic’s lead before the interval settled the outcome.

Furuhashi was clean through on Butland shortly before the hour but chipped wide. The Rangers goalkeeper had to act smartly after Robin Pröpper deflected a cross towards his own net. Another long-range strike added gloss to Celtic’s victory, Callum McGregor the scorer as Butland was beaten high to his right.

Rodgers was left to reflect on a “fantastic performance” during which he believed Celtic were “electric going forward”. The strongest praise from the manager, though, came for the Celtic directors who matched his transfer window ambitions. Arne Engels, who made his debut as a substitute, became Celtic’s record signing when arriving from Augsburg for £11m. “The club has been first-class in terms of bringing in players at a level we wanted,” Rodgers said. “We have done some great business.

“I am very happy. I think that it’s very, very hard to do everything you want to do in one window but if you look at the work that has gone into here at the club with the players, not just the players in but players going out, there’s been so much that we’ve needed to do in order to get the squad to where we want it to be. A manager will always want a little bit more but I can’t complain. We’ve done some great work over the course of the window with the players we’ve brought in.”

Rodgers had no cause to criticise his players. But they should probably have pressed home their advantage to a greater extent. Celtic seemed safe in the knowledge Rangers had no available route back into proceedings.

Even those in the stands seemed rather bored with it all. That is at least one explanation for the belting out of verse in support of the IRA as stoppage time played out. Neither Celtic nor the Scottish football authorities do nearly enough to address this embarrassing dirge, which hauls the game back to a time everyone else gladly moved on from long ago. Celtic have so much else to cheer and celebrate; there is no sign of that stopping any time soon.