Hugo Rodallega's 78th-minute header was enough for Wigan to win at Stoke, while Wolves went down 3-2 at home to Blackburn Rovers, who quickly allayed their own slight relegation fears, yet still avoided the drop.
"It is an amazing, amazing achievement," Roberto Martinez, who picked the perfect time to oversee back-to-back wins for the first time in two years as Wigan manager, said in a televised interview.
The manner in which defeat came to Blackpool, 4-2 against the champions Manchester United, was most brutal.
They could have been ahead as early as 24 seconds into the game when a golden chance presented itself to Keith Southern, one of the club's longest-serving players.
He passed it up, but they continued to play with the verve that has won them many friends in their first season of Premier League football, and even held a 2-1 lead at the start of the second-half.
Their ensuing capitulation was as cruel as it was inevitable, though. They sacrificed the lead for good when Ian Evatt, another player who has played in excess of 200 games for the club, struck an own goal.
Their misery was complete when Michael Owen, the striker who was about to collect the first league winner's medal of his illustrious career, hit United's fourth.
"After taking the lead, we had started to believe we can do this," said Ian Holloway, the Blackpool manager.
"You saw the way we played, the chances we created, we've got to take those. That aside, we've been absolutely outstanding and it's hard to take."
Wolves fans will still be wondering this morning how they managed to dodge the bullet. They looked certain to go down when they slumped 3-0 down against Blackburn, only for Stephen Hunt's 87th-minute goal to edge them ahead of Birmingham, their Midlands rivals, on goals scored.
Moments later, Birmingham's fate was sealed when Roman Pavlyuchenko drilled his second long-range goal of the game, to give Tottenham Hotspur a 2-1 win at White Hart Lane.
Though the main drama centred on the foot of the table, some significant side issues were also resolved.
Manchester City beat Bolton Wanderers and earned direct passage to the Champions League, ahead of Arsenal, who face a qualifying round, while Tottenham's win and Liverpool's defeat at Aston Villa gave the London club fifth place and a spot in next season's Europa League.