The victory saw them end the season in seventh place in the Premiership, with 53 points to their name, their best Premiership finish ever and their best top flight finish for more than half a century.
As importantly, or at least so it seemed to the fans, they discarded the mantle of perennial last day losers, winning their first, final day game, for 17 years.
Their start may have been understandably nervous, but with the visitors showing little by way of invention, they gradually overwhelmed Paul Sturrock's side, scoring twice in a 15-minute period, either side of the break.
Jason Euell latched onto a neat Paolo Di Canio flick on after 36 minutes, before sliding the ball precisely under the dive of young Southampton keeper Alan Blayney, to break the deadlock, and end another piece of unfortunate history for Alan Curbishley's men.
Before Euell's strike, their last goal on the season's final afternoon, had been seven long years earlier.
Taking inspiration from the vociferous crowd, they wasted little time after the re-start in doubling their lead. Matt Holland floated an inch-perfect ball to the far post, where Carlton Cole, who replaced the injured Di Canio just before half-time, controlled and volleyed beyond Blayney, into the far corner.
Saints fought back and after David Prutton's strike, 25 minutes from time, flew past Dean Kiely at the near post, they might have gone on to claim something from the encounter, but Charlton were not prepared to let their advantage fade away.
Alan Curbishley's delight at the final whistle was clear for all to see.