Often at the darkest moments there’s a glimmer of light.

It was Johnnie Jackson’s thunderbolt volley half an hour into this largely flat and languid affair between Charlton and Scunthorpe that shone above all else.

As the captain wheeled away in joyous celebration, he marked it with as much delight as any of his other 54 goals in a Charlton shirt.

This was despite the club at its lowest ebb – epitomised by the empty seats staring back at him (the attendance was 9,088).

Jackson is now the manager in waiting. And he may not have to wait long judging by another worrying performance.

Tony Watt of Charlton Athletic celebrates scoring during the Sky Bet League One match between Charlton Athletic and Scunthorpe United

When Josh Magennis was forced off with injury around the hour mark it was a blow to the Addicks.

But Karl Robinson’s answer was to bring on the static Andrew Crofts. All of a sudden Charlton were without their main attacking threat and lumbered with an extra midfielder.

Scunthorpe, awful up until that moment, went to plan B, launching balls over the top and breaking through the Charlton back line with devastating effect.

Time and time again the Addicks were exposed until with 15 minutes to go Kevin Van Veen levelled the scores form a Declan Rudd fumble.

Charlton had lost the lead yet again. And this one was down to the manager.

Joe Aribo of Charlton Athletic battles with Murray Wallace of Scunthorpe United

Finally seeing a flaw in his masterplan with two points down the drain, Robinson sought to rectify matters by taking off Charlton’s only other striker – Lee Novak – for perennial underachiever Tony Watt.

Evoking memories of “that Champions League night against Barcelona” in 2012, Watt tried to latch on to a through ball by Ricky Holmes.

But in what looked like a race through treacle, the Scotland international was beaten to the ball, and nearly lapped by Scunthorpe tanker Murray Wallace.

Blowing on his trusty dice one final time, Robinson then dragged off makeshift forward Holmes, who had been the creator of all things good, for rookie Karlan Ahearne-Grant.

Ricky Holmes of Charlton Athletic battles with Stephen Dawson of Scunthorpe United

Somehow, and almost out of nowhere, Charlton were gifted a last minute penalty as Jorge Teixeira was dragged back in the box by Wallace.

Up stepped Tony Watt – looking more capable with no-one in pursuit – who fired home the winner.

It was the first win in nine for Charlton, against a team battling for automatic promotion.

After a truly awful run of results maybe this is the key victory which would help to stave off a relegation to the bottom tier of the league.

But this is no time to celebrate. The cracks have just been papered over.