Adam Hammill's stunning strike helped Barnsley to a 3-1 win in the League One play-off final against Millwall at Wembley.
Barnsley secured a return to the Championship with a 3-1 win over Millwall in Sunday's League One play-off final.
The Yorkshire side, bottom of the league table in December, capped a remarkable turnaround in 2016 with a deserved win at Wembley that seals their place back in the second tier of English football.
Barnsley, who only reached the play-offs by virtue of a better goal difference than Scunthorpe United, made an ideal start as they took the lead with just two minutes played thanks to on-loan Manchester United striker Ashley Fletcher's fine finish.
Caretaker boss Paul Heckingbottom, who steered his side to victory in the Football League Trophy final at Wembley last month, led the celebrations when Barnsley doubled their lead through Adam Hammill's sumptuous strike from 25 yards out.
Millwall snatched a lifeline before half-time when Mark Beevers showed great strength to hold off a challenge before turning to sweep the ball high into the net, but they failed to create any sustained pressure in the second half.
And Barnsley made sure of their victory 16 minutes from time, when Lloyd Isgrove leaped highest to power home a header from Hammill's corner, allowing their travelling fans to celebrate the most unlikely of promotion stories.