Eight months after football closed its doors, 2,000 fans were back at the 27,111-capacity ground for the League One clash, marking what clubs hope will be the first step towards a return to normality in the not-so-distant future.
Addicks manager Lee Bowyer has complained that behind-closed-doors matches have killed home advantage but ironically his side suffered just their second home defeat this season – the other coming against Doncaster in September, when 1,000 fans were at the Valley for a pilot event.
The extra pressure on Charlton might have been a factor, as Bowyer's side never found their rhythm and were undone by Scott Fraser's 75th-minute strike.
Before kick-off, it was genuinely uplifting to see fans filing through the streets towards the stadium again, many following advice by avoiding public transport, in spite of the rain.
The club had taken steps to avoid crowding, with each supporter given one of four timeslots to arrive at the ground, and the majority were already in their seats when the Addicks emerged for the warm-up to their first proper reception since the pilot event.
During the shutout, it has been easy to become accustomed to deserted grounds, where the players' shouts and the eerie hum of electricity have formed the soundtrack to elite football.
So it was particularly stirring to hear the roar of the crowd as Charlton re-emerged for kick-off, the supporters following the stadium announcer's pre-match command to make '2,000 sound like 27,000'.
After such a long absence, even the familiar groans of frustration – which soon began as Charlton spluttered in the early stages – were oddly comforting.
So too were all those reactions that broadcasters' artificial crowd noise will never be able to mimic.
The West Stand greeted a booking for an MK Dons coach midway through the first half with ironic cheers and there were sounds of mingled excitement and frustration as Charlton attacked while visiting Fraser lay prone on the turf, signalling for treatment.
A collective intake of breath and 'ooohhh' met any dangerous Charlton cross into the Dons box – and there were several but Conor Washington was rarely close enough to connect.
Even the birthday messages to fans, read out by the stadium announcer at half-time, made a welcome return.
There was plenty that was unfamiliar, too, including announcements before kick-off, at half-time and after the final whistle advising fans to pass each other back-to-back in the aisles and wear their face-masks at all times, except when eating or drinking.
Stewards sporadically stalked up and down the walkways, checking fans were following protocol, and all kiosks were closed, with the club having decided to wait until supporters are used to the protocols before selling food, drink and programmes.
The majority of noise came from the North Stand – known as the Covered End – but supporters were given a fright when Fraser strolled through Charlton's rearguard and forced Ben Amos into a smart save for the best chance of the first half.
Charlton continued to look second best after the interval and soon the 2,000 found themselves needing to lift their team, as MK Dons sensed an important win.
One of the features of so few fans was that it was easy to hear individual cries of frustration, which began to punctuate the second half as Russell Martin's side remained on top, despite a succession of substitutions by Bowyer.
Just as Charlton appeared to have found a foothold, with captain Darren Pratley going close, Dons broke and the excellent Fraser delivered the decisive blow, firing low under Amos.
The biggest cheer of the night nearly came in stoppage-time, however, when Pratley struck the crossbar with the Dons 'keeper stranded. It could scarcely have been closer.
As the supporters warmly applauded the hosts at full-time and filed out of the stadium – block-by-block and row-by-row to avoid crowding – they must have been left with a sense of what could have been.
But for the Charlton fans – and supporters up and down the country – there should now be other opportunities to experience all the varied emotions of matchday again.