Portsmouth and Stockport County have each sealed the League One and League Two titles respectively on Tuesday night.
Having missed out on an opportunity to win the third-tier trophy and promotion at the weekend, Pompey were left knowing that a win over Barnsley at Fratton Park would secure both.
While John Mousinho's side did not have things their own way, they twice came from behind to secure a 3-2 victory on the South coast.
Goals from Devante Cole and John McAtee either side of a Kusini Yengi effort appeared to put the playoff-chasing Tykes in control, only for Colby Bishop to equalise from the spot with seven minutes remaining.
A share of the spoils would have been enough for Portsmouth to seal promotion, but Conor Shaughnessy's goal in the 89th minute sparked wild scenes as his side secured the title with two matches to spare, as well as a return to the Championship after 12 years away.
Stockport County win League Two title
Meanwhile, Stockport were only left to win the League Two title after they and Wrexham had promotion confirmed at the weekend.
Sealing the trophy was never in any doubt as they thrashed Notts County, with Paddy Madden scoring a hat-trick inside the first 40 minutes of the contest at Meadow Lane.
Antoni Sarcevic added a fourth after the break, and although Macauley Longstaff and Dan Crowley halved the deficit, Ethan Pye confirmed a 5-2 victory with six minutes remaining.
Mansfield Town were also able to claim the final automatic promotion spot through their 2-1 triumph over Accrington Stanley.
George Maris and Stephen Quinn scored the goals that proved pivotal, with Tommy Leigh's late effort for the visitors proving inconsequential, as Nigel Clough's side moved above Wrexham on goal difference.
At the bottom end of the table, Forest Green Rovers have been relegated to the National League courtesy of Colchester United posting a 2-0 win over Grimsby Town, leaving Forest Green eight points adrift with just two games to play.
