If ever a stadium can be rocked by silence, this was the moment. With no visiting fans allowed at any of this season’s Glasgow derbies, Ryan Naderi’s winning goal was met with nothing but the banging of fists of the clear plastic of the Rangers bench and the shouting of the broadcast commentators. A screaming void of apathy and atrophy, the sound of a beckoning abyss, of three straight Celtic defeats and a title race blowing open.

In the coming three weeks, as club football dissolves for the international break, noises and voices will pour into the void: some helpful and some not. This, of course, is a familiar feeling for any club of Celtic’s size, and naturally the temptation will be to block out the noise, stay the course. This would be a grave mistake. If last season’s double illustrated the way this club can still rise above adversity, there can no longer be any hiding place, no equivocation with the alarming drop in standards that was evident here.