Karl Robinson is still awaiting his first victory as Charlton boss after seeing his new side beaten at home by play-off chasing Peterborough.
Following early efforts from Shaquile Coulthirst and Leonardo Da Silva Lopes, Grant McCann's side deservedly took the lead after 21 minutes with Ryan Tafazolli rising highest to nod in Paul Taylor's free-kick.
Lopes could have doubled Posh's lead just before half-time but his effort from just inside the penalty area was easily saved by Dillon Phillips.
The Addicks came out on the front foot after the break and went close through Josh Magennis, but the forward's effort ricocheted back off the inside of the far post.
To frustrate the hosts further, Jordan Botaka then saw a deflected effort loop up onto the crossbar with Luke McGee beaten in the 55th minute as Charlton searched for an equaliser.
Peterborough doubled their advantage in the 66th minute courtesy of a superb Gwion Edwards solo effort to seal an impressive away victory.
Report supplied by the Press Association
