The Posh opened the scoring through Kwame Poku, and would’ve had a second in the first half but for an impressive penalty stop by Dan Grimshaw.
Neil Critchley’s side went down to 10-men shortly after the restart, following Olly Casey’s red card, with Harrison Burrows, Ricky Jade Jones and Ephron Mason-Clark all going on to find the back of the net for the visitors- while goals from Kenny Dougall and Sonny Carey proved to be nothing more than consolations.
Peterborough took the lead in the 15th minute, after a very quiet start to the game.
Mason-Clark crossed the ball to the back post from the left wing, with Poku arriving to control and finish into the bottom corner past Grimshaw.
Blackpool’s first attempt at goal came just over 10 minutes later.
CJ Hamilton did well to win back possession in the Peterborough box, with the ball coming to Kylian Kouassi- who dragged his effort wide of the post.
Ahead of half time, Darren Ferguson’s side were awarded a penalty, following a trip on Mason-Clark from Matthew Pennington.
The man who won the spot kick stepped up to take it, but was denied by Grimshaw- with the keeper guessing the right way.
Down the other end, Kouassi had another opportunity to level the scores, but couldn’t keep his header down after some good work from Sonny Carey.
A minute into the second half, Critchley’s side had their numbers reduced, with Casey bringing down Jones on the edge of the box as he was about to run through on goal.
From the resulting free kick, Burrows curled the ball around the wall into the bottom corner to make it 2-0.
A third soon followed, with Jones slotting through the legs of Grimshaw after being played in by Poku.
On the hour mark, Dougall pulled a goal back for the Seasiders, which sparked new life into the game.
That was quickly followed by a strike from Carey, with the midfielder finishing on the rebound to close the gap further.
At the beginning of stoppage time, Peterborough sealed their victory.
Following a mistake at the back from Blackpool, Mason-Clark took the ball around Grimshaw to make it 4-2.