Story of the game
For a largely meaningless game, the first half was played at a good intensity.
Peterborough looked confident in possession early on, and forced Chris Maxwell into an early save, when Jack Taylor broke into the box.
Ricky Jade-Jones and Harrison Burrows caused plenty of problems in the first ten minutes, driving at the Blackpool defence, with the former also testing Maxwell with a curling effort.
Taylor called the visiting goalkeeper into action again with a looping header before Sammie Szmodics saw an effort put behind for a corner by Maxwell’s legs.
Blackpool saw a lot of the ball but were not creating anything meaningful, a whipped free-kick by Luke Garbutt the closest they came in the opening half an hour.
You did start to wonder if Peterborough would begin to rue the missed chances, but did take the lead ten minutes before half time.
Taylor won the ball back with a huge tackle inside his own half before Kwame Poku slipped the ball through to the Posh captain who rounded a stranded Maxwell and curled the ball into an empty net.
And he should have doubled his team’s lead moments later when his side-footed volley sailed over the bar.
The visitors woke up after this and started to have a few chances themselves, but nothing that troubled ‘keeper Cornell.
Both teams were forced into changes before the interval due to slipping on the pitch, as Richard Keogh was replaced first by Marvin Ekpiteta for the visitors, Jeando Fuchs was replaced by Jorge Grant for Posh.
The second half started with the hosts in the ascendency, with Joe Ward putting in two inviting crosses that evaded everyone.
But, for all their comfort in possession, they almost shot themselves in the foot by overplaying, as Hamilton pounced on loose pass from Ward, but his cross couldn’t find a man in black.
From there, Posh broke and Poku had a shot fly over the bar before a dangerous delivery from Ward again was claimed by the impressive Maxwell.
And it wasn’t long before Peterborough doubled their advantage through Szmodics.
Jade-Jones found himself in acres of space in the middle of the park and was able to lift a delightful little ball through for the midfielder who was able to just get their ahead of Maxwell and prod it home.
The Cambridgeshire side continued to knock the ball around with confidence, and soon found themselves three goals to the good.
Burrows was slipped in down the left-hand side, and his driven centre found the unmarked Szmodics to tap into the back of the net in front of the London Road End.
Blackpool rarely threatened throughout the second half, Sonny Carey’s deflected effort the best of their sporadic chances on a dismal day out for the 1,100 supporters who made the trip from Lancashire.
Peterborough looked for more, with Maxwell getting down well to claim low crosses first from substitute Joel Randall and then from Szmodics.
And they did eventually find their fourth, and it was the pick of the lot… to this point anyway.
Burrows whipped in a beautiful cross for Marriott, who had the freedom of London Road to volley home.
But they were not done their, with Taylor adding his name to the scoresheet.
He picked up the loose ball and, under the instruction of those behind the goal, took aim and curled the ball off the underside of the cross bar and into the net.
The Blackpool fans were in fine voice to the end, as Stewart put one over the bar in front of them with the last chance of the game.
It was the performance Posh had needed all season, and it came obviously too late, but what a way to say goodbye to the Championship.
Cornell; Ward, Knight, Edwards, Burrows; Poku, Taylor, Fuchs, Szmodics; Clarke-Harris, Jade-Jones.
Maxwell; Connolly, Casey, Keogh, Garbutt; Hamilton, Stewart, Carey, Dale; Beesley, Yates.