Simon Church’s second-half strike doubled the visitors’ lead after Chris Eagles had put them in front in the first period against his old club and Johann Berg Gudmundsson’s third added insult to injury.
Blackpool are now without a win in their last 10 games and have lost their last six – taking their tally of defeats in the league to 24.
The Seasiders had the first effort after just 10 seconds as Andrea Orlandi cut in from the right but his curled effort was comfortably saved by Stephen Henderson.
Blackpool went close again after 19 minutes as Tom Barkhuizen broke down the right and unleashed a shot from 20 yards which whistled just over the bar.
The home side continued to look the most likely to open the scoring and Orlandi drifted in from the right again after 25 minutes, but dragged his left-footed shot wide of the near post from the edge of the area.
It was Charlton however who took the lead on the half hour after a terrific team move was tapped home by Eagles from six yards. Tony Watt’s backheel put the away side in behind and Eagles was on hand to pounce when Gudmundsson’s shot was saved by Joe Lewis.
David Perkins had a chance to equalise after 39 minutes, but his tame left-footed strike from the edge of the area was easy for Henderson to hold after good work to set him up by Orlandi from the left.
Lee Clark’s side started the second half on the front foot and Barkhuizen fired a shot with the outside of his right boot – from the edge of the box – inches wide of the far post three minutes in.
Blackpool continued to push forward but with little effect as Perkins launched an ambitious 30-yard drive after 56 minutes which was straight at Henderson.
It was Charlton who struck once again against the run of play on the hour mark as Gudmundsson’s shot from the edge of the 18-yard box was gathered by Church and the striker lashed home a close-range effort with his right foot.
Andrea Orlandi then missed a golden opportunity to pull one back after 64 minutes as the ball broke to him in the six-yard box but he skewed his left-footed shot high over the bar.
Blackpool almost pulled a goal back in the 79th minute from substitute Bright Osayi-Samuel’s first touch, but his left-footed prod from 12 yards was tipped over by Henderson.
Charlton made it 3-0 with two minutes remaining when Gudmundsson curled home a free-kick from the edge of the area into the top left-hand corner to seal the win.