Sheffield Wednesday earned promotion back to the Championship after a 2-0 win over relegated Wycombe kept them ahead of city rivals Sheffield United.
Wednesday knew they only needed to match the Blades' result to secure promotion alongside Charlton after two seasons in the third tier and they took the lead through Michail Antonio in the 25th minute.
Wycombe's defensive record is the reason they will return to League Two and Nile Ranger was given far too much space to head in Chris Lines' free-kick seven minutes after half-time and seal victory.
United's disappointment was compounded as they could only draw 2-2 with another relegated side, Exeter, who went ahead in the 24th minute through a fine goal from Alan Gow.
The visitors were then reduced to 10 men when James Beattie was shown a straight red card for a tackle on James Dunne.
Lee Williamson levelled matters a minute before the break and Kevin McDonald put United ahead within two minutes of the restart, but Scot Bennett equalised late on, and if the Blades are to bounce straight back to the Championship it must be through the play-offs.
Stevenage kept alive their hopes of two straight promotions by securing the final play-off spot and a clash against United with a 3-0 win over Bury.
Craig Reid opened the scoring in the 24th minute, Joel Byrom gave Stevenage breathing space with a 77th-minute penalty and Chris Beardsley added gloss in injury time.
That result meant Notts County missed out on the play-offs on goal difference despite a 4-1 victory over Colchester, with Jeff Hughes, Daniel Bogdanovic, Alan Judge and Kieron Freeman scoring their goals.
Carlisle also went into the day with an outside chance of making the top six but it was out of their hands and they went down 2-1 to Oldham.
James Tarkowski put the hosts ahead in the 49th minute and, although Tom Taiwo equalised for United, parity lasted only four minutes before Oumare Tounkara headed a 72nd-minute winner.
Huddersfield jumped above MK Dons, who they will meet in the play-off semi-finals, into fourth thanks to a 2-0 victory over Yeovil - Lee Novak and Daniel Ward netting for the Terriers.
The Dons will go into that two-legged tie on a losing note after Will Grigg scored the only goal in a 1-0 win for Walsall.
Champions Charlton ended their season with an entertaining 3-2 victory over Hartlepool. Peter Hartley gave Pools the lead but Danny Hollands, Danny Haynes and Yann Kermorgant netted in quick succession late on before Gary Liddle grabbed a second for the visitors.
Brentford, Bournemouth and Leyton Orient all ended the season with victories, the Bees seeing off Chesterfield 3-2, Bournemouth beating Preston 1-0 and Orient defeating bottom side Rochdale 2-1, while Tranmere and Scunthorpe drew 1-1.