In a tense final day of the regular season in the Championship, English football's second division, Sheffield Wednesday have been relegated after drawing a survival shoot-out 2-2 with Crystal Palace at Hillsborough.
Blackpool, who last saw top-flight action in 1971, secured a place in the play-offs alongside Nottingham Forest, Cardiff City and Leicester City.
Wednesday needed to win their final game against Palace to survive - and send the Londoners down.
Third-placed Forest were already assured of a play-off place and will face Blackpool next weekend after the Lancashire side came from behind to draw 1-1 at home with Bristol City.
Cardiff and Leicester will meet in the other playoff semi-final with the final at Wembley on May 22.
West Bromwich Albion and champions Newcastle United had already secured the automatic promotion places and Newcastle signed off with a 1-0 win at Queens Park Rangers.