Barnsley have joined Southend United and Colchester United in The Championship after beating Swansea City 4-3 on penalties after a thrilling 2-2 extra-time draw.
Goals from Paul Hayes and Daniel Nardiello for The Tykes were equalled by strikes from Swansea's Rory Fallon and Andy Robinson in Cardiff, as 120 minutes of football could not separate either side in Saturday's League One play-off final.
With Barnsley perfect in the penalty shoot-out, a miss from Adebayo Akinfenwa and Nick Colgan's save to Alan Tate's spot kick meant Andy Ritchie's side claimed promotion.
Despite the Millennium Stadium pitch being in very poor condition, both sides contributed to an entertaining contest.
The Swans started the stronger of the two sides, with Owain Tudur-Jones shooting wide before Sam Ricketts missed the head of Fallon with his cross from the left.
At the other end, Nardiello struck wide for The Tykes before Brian Howard forced Swansea goalkeeper Willy Gueret into a superb diving save with his low shot.
Though Swansea looked the better side, Barnsley broke the deadlock on 19 minutes after Swansea's Kevin Austin failed to clear Martin Devaney's cross from the right and the ball fell for Hayes to volley through Tate's legs and past Gueret.
Swansea responded with two efforts off target from Ricketts, while Leon Knight was harshly adjudged offside after going clean through on Tykes goalkeeper Colgan.
Kenny Jackett's side persisted and from Garry Monk's free kick, Tudur-Jones flicked the ball into the path of Fallon and with a spectacular overhead kick, the former Barnsley trainee levelled matters on 28 minutes.
Five minutes before the break, Swansea claimed the lead in comical circumstances, as Robinson's strike from a short indirect free kick struck the hands of Colgan and deflected into the Barnsley keeper's own goal for 2-1.
It was an awful goalkeeping error by Colgan, but he made amends just before the break when he stopped Robinson's fierce strike on the goal line with his foot, as Knight rushed in looking for the rebound.
The second half saw Swansea try and build on their slim lead, with Barnsley defender Paul Reid making a timely intervention to stop Knight striking home Fallon's knock back.
Barnsley kept pressing for an equaliser and were rewarded just after the hour mark, as Nardiello's right-footed free kick left a statuesque Gueret to watch the ball roll into an empty net for 2-2.
The Tykes then had a glorious chance to win the contest in the dying stages, but captain Reid's downward header from Devaney's cross bounced agonisingly wide before Swansea's Tate failed to convert Leon Britton's pass from close range in injury time.
The match moved into extra time, with Swansea substitute Lee Trundle testing Colgan with a low drive before Akinfenwa narrowly missed the target seconds after coming on in the first extra-time period.
Swansea dominated the next 15-minute period, with Trundle shooting wide after turning and going by Barnsley's Antony Kay, as both sides had to settle for a penalty shoot-out.
In the shoot-out, Akinfenwa's miss meant Tate had to score his spot kick in the fifth and final round of penalties, but Colgan redeemed himself for his earlier error by saving his strike and confirming Barnsley's place in The Championship.