Luton Town and Barnsley have both been promoted to the Championship after slip-ups for Portsmouth and Sunderland.
Portsmouth and Sunderland had a game in hand going into midweek and still had hopes of catching the top two in League One.
But Pompey suffered a 3-2 defeat at home by Peterborough United, while a 95th minute goal saw Sunderland defeated away at Fleetwood Town.
The result ensures Luton have registered back-to-back promotions, with a season of fine form under Nathan Jones and his successor Mick Harford seeing them successfully build on their promotion from League Two last season. On their way, they have scored 87 goals in the League One season – the highest of anyone in the third tier.
The Hatters will compete in the Championship for the first time since the 2006-07 season, after a campaign that has so far seen them break the 90 point barrier.
Luton enter their final game of the season against Oxford United at Kenilworth Road ahead of Barnsley on goal difference, knowing victory by a bigger margin than the Tykes will secure them the League One title.
Anything less than a point could let in the South Yorkshire side, who travel to Bristol Rovers.