Birmingham City have secured automatic promotion to the WSL after a dramatic winner-takes-all finale saw the Blues beat title rivals Charlton Athletic 2-0 on Saturday. A double from club record signing Wilma Leidhammar secured the win for Birmingham City, handing them the WSL 2 title. Charlton, who needed a win or a draw to confirm their automatic promotion, will enter a playoff decider against the WSL's bottom side, Leicester City, on May 23 -- which was confirmed following the Foxes' 7-0 loss against Arsenal on Wednesday. With the WSL expanding from 12 to 14 teams next season, both Palace and the Blues were able to confirm their spots in the league, while Charlton, who have led the way for the majority of the campaign, were left in third place, just outside of the automatic promotion places. Palace secured an immediate return to the WSL after just one season in the second division, while Birmingham return after four years away, following their heartbreaking final-day loss to London City Lionesses last season. At the Valley, Birmingham City had to hold their lead for 13 extra injury-time minutes before they could begin their celebrations and despite Charlton's best efforts, the full-time whistle cued wild celebrations as the visitors were crowned champions.