Goals from Johnnie Jackson and Scott Wagstaff handed the Addicks a 2-1 win with Nathan Eccleston netting a late consolation.
The Seasiders are looking for yet another boss after Michael Appleton quit to join Blackburn just 24 hours earlier.
Assistant manager Steve Thompson took temporary charge, just as he had two months ago when Ian Holloway also jumped ship to a rival Championship side, Crystal Palace.
Sean O'Driscoll is among the favourites for the role while another name in the frame is Blackpool's veteran striker Kevin Phillips.
But at the moment the former England international is still leading the line at the age of 39, and he missed a gilt-edged chance to give the beleaguered visitors the lead after just two minutes.
Phillips was unmarked, three yards out, when he met Nathan Delfouneso's cross but his header drifted back across goal, rolled against the far post and was hacked clear by Matt Taylor.
Instead Charlton recovered from their slow start and almost went ahead when Dale Stephens' corner found Taylor at the far post, only this time his header was nodded off the line by Delfouneso.
But Charlton did take the lead in the 23rd minute when Chris Solly's pass was deflected into the path of Jackson.
The midfielder's speculative effort from the edge of the box somehow bobbled its way past the diving Matt Gilks and into the bottom corner of the net.
Blackpool rallied before half-time and Ben Hamer saved from Isaiah Osbourne and Tom Ince.
But in stoppage time Charlton grabbed their second when a slick move ended with Lawrie Wilson crossing to Yann Kermorgant.
His header was well saved by Gilks but the ball fell to the feet of Wagstaff, who rifled it back past the grounded keeper and into the net.
It was the young winger's second goal of the season on only his second appearance.
Blackpool spent the majority of the second half camped in Charlton's half, with Ince's touch and pace impressive but his finishing wayward.
Phillips' race was run after 77 minutes and substitute Eccleston finally found the way to goal with an 18-yard drive in stoppage time, but Charlton were not to be denied only their fourth home win of the campaign.