Runaway League One leaders Birmingham City sealed promotion back to the Championship at the first attempt with six games to spare thanks to victory at Peterborough.
Posh’s Kwame Poku put the party on hold when he equalised three minutes after Alfie May had put the visitors ahead.
But Taylor Gardner-Hickman restored Blues’ lead eight minutes before the interval with what turned out to be the winner.
Big-spending City, relegated last season, are 14 points clear of second-placed Wrexham and now cannot be caught by third-placed Wycombe, despite the Chairboys’ win at Huddersfield.
They have led the table for most of the campaign – boss Chris Davies’ first season in management – and have achieved their expected promotion at a canter.
With the travelling fans in celebratory mood, May opened the scoring by heading in Gardner-Hickman’s excellent ball in from the left.
Poku then thumped Posh level from near the edge of the penalty area after Birmingham could only half-clear a corner.
But Gardner-Hickman sealed the win and promotion by firing under keeper Nicholas Bilokapic from the left side of the box after collecting Marc Leonard’s pass.
