Peterborough were knocked off the top of Sky Bet League One after Gary Madine's last-gasp strike snatched Blackpool a 2-1 win.
The resurgent visitors continued their charge with a fifth successive victory in all competitions.
Striker Madine pounced from close range in the last minute to tuck away a low CJ Hamilton cross from the right and settle the game - shortly after Posh thought they had salvaged a point through birthday boy Frankie Kent.
The central defender celebrated turning 25 by heading Posh level in the 84th minute after being picked out by Dan Butler's corner.
But the celebrations proved to be short-lived as the visitors responded impressively to earn a deserved success courtesy of Madine.
The Seasiders had hit the front in the 19th minute when Jerry Yates turned smartly to fire past goalkeeper Christy Pym after being picked out by Sulley Kaikai's cross from the left.
They were guilty of squandering a host of other chances, with Yates blasting wide early on before Kaikai fluffed two opportunities after the break.