Miles Leaburn scored twice for Charlton to end Wycombe's 19-game undefeated run in League One.
Addicks forward Leaburn struck in quick succession at the start of the second half to take his goal tally to eight in all competitions this season.
He produced a first-time deft touch to turn Josh Edwards' cross past Chairboys goalkeeper Franco Ravizzoli in the 46th minute.
Leaburn added to his tally in the 52nd minute, racing onto Luke Berry's through-ball to chip Ravizzoli.
Tyreece Campbell had a big chance to add a third for Charlton but lashed over from Macaulay Gillesphey's pass which had put the winger in on the left of the penalty area.
Wycombe's top scorer Richard Kone reduced the deficit in the 84th minute, producing a smart turn and low finish across Charlton goalkeeper Ashley Maynard-Brewer for his 15th goal of the campaign.
Wanderers are the top scorers in the division but struggled to create chances as they suffered an away loss for the first time since the opening day of the campaign.
Report supplied by PA Media.