Portsmouth and Hartlepool United have been relegated to League Two following Oldham Athletic's 1-0 victory over Yeovil Town.
Matt Smith's goal at Boundary Park was enough to send both sides into the fourth tier of English football, despite neither having played this evening.
Oldham's win lifts them five points clear of the drop zone with a game in hand as both Colchester United and Scunthorpe United below them lost.
Scunthorpe were defeated 2-1 at bottom club Bury, whose fate was already sealed, while Colchester went down 2-0 at home to seventh-placed MK Dons.
At the other end of the table, Brentford missed out on the chance to break into the top two following an eventful 2-2 draw with promotion rivals Sheffield United.
Three players were shown red cards during the Bramall Lane clash and penalties were awarded to either side. Bradley Wright-Phillips netted Brentford's equaliser with one minute left to play.
Meanwhile, Adam Rooney bagged a brace as Swindon Town thrashed Crewe Alexandra 4-1 to consolidate their position in sixth place.
Results in full: Bury 2-1 Scunthorpe, Colchester 0-2 MK Dons, Sheff Utd 2-2 Brentford, Swindon 4-1 Crewe Alexandra, Oldham 1-0 Yeovil
