And there was no mistaking the moment that really got the crowd going on a night when – by their recent standards – the Scottish champions produced a tame win over an impressively obdurate St Mirren to retain pole position in the Scottish Premiership.
It came when James Forrest scored eight minutes into the second period to double his team’s post-interval lead.
The goal, the winger’s 10th of the season, came only hours after a deal to keep him at Celtic until 2023 was signed by a one-club man whose modest demeanour never disguises his affection for the team he has respresented with distinction for nearly a decade.
That was recognised in the reaction to the goal, netted when the ball was shifted from Odsonne Edouard to Ryan Christie and then to Forrest, who set himself and beat Vaclav Hladky with a powerful raking drive.
A song was struck up for the 28-year-old, whose unaffected manner hasn’t made him the sort to inspire anthems.
And it was a song that once belonged to Brendan Rodgers, with the erroneous prediction that the now Leicester City manager would be here for “10 in a row”.
Instead, the “this is how it feels to be Celtic” ditty, with its “champions again don’t you know” line, was adapted to make “Jamesey Forrest” the subject.
And it is entirely possible he could play his part in title wins over the next two years to reach the magical, and unprecedented, 10 in total.
Celtic looked well short of the side that had seemed energised by this quest in demolishing Aberdeen and Ross County in their past two league games – and overcoming Lazio in bteween.
They were faced by a Jim Goodwin side drilled as efficiently as a North Korean army unit on parade.
For long spells in the first period, left back Greg Taylor must have feared he had put a hex on the home side. At long last handed a debut in Celtic colours, having previously failed to earn any minutes since his £2 million signing from Kilmarnock, it was the Paisley club who appeared at one with themselves as Celtic displayed a raggedness.
Taylor, pictured, wasn’t at fault for that, and he was a hungry presence down the left, as might be expected in the Scotland international’s first senior outing since August 17.
Too eager, indeed, for Kyle Magennis, who was booked after unceremoniously hauling him back midway through the first period.
As a collective, the Paisley side, who have now dropped to the bottom of the Premiership, succeeded in keeping Celtic on a leash in a manner beyond many other sides in Scotland – at least in the early stages.
Their shape and system resulted in Odsonne Edouard being largely smothered, but it did not preclude the league’s lowest scorers (an unfortunate statistic slightly offset by only Celtic and Rangers having conceded fewer goals) from breaking upfield.
Jon Obika drew a save from Celtic keeper Fraser Forster after he penetrated the home backline thanks to a smart Sean McLoughlin through ball, and the visitors fashioned a couple of other half chances.
Celtic had their own opportunities, of course, and Christopher Jullien headed over from a Christie corner before Ryan Flynn cleared on the line when the central defender hit the target in an identical situation.
Just before the interval, Forrest cracked the post with an effort with the outside of his right foot – an indication that the night would ultimately belong to him.
Before he was granted the honour of the Rodgers song, though, Celtic had broken St Mirren’s resistance when Edouard found the goal frame with a curling effort, Christie cannoned the rebound off Calum Waters and the ball diverted into the path of Mohamed Elyounoussi, who drilled in from eight yards.
It was a wonder that Forrest wasn’t involved in a week when it was revealed he has had more Celtic assists than any other player in the 21st century.
Even with a testimonial surely in the offing, the 81-goal winger will be assisting the club’s cause for many more years of this century.