Plymouth Argyle put themselves in pole position to clinch the title with a late victory over Crewe Alexandra at Home Park.
James Jones put the visitors ahead but two goals in five second-half minutes from Ryan Taylor and Nathan Blissett turned the match on its head and sent Argyle to the summit.
The Devonshire club’s win put them one point ahead of Doncaster Rovers who suffered a shock home defeat to Exeter City.
The Grecians booked their place in the play-offs with three points against Darren Ferguson’s side at the Keepmoat.
Portsmouth boosted their title chances with victory and dented Mansfield Town’s top seven hopes in the process.
Carl Baker grabbed the only goal of a tense game at Field Mill which saw referee Lee Swabey dish out nine yellow cards.
Blackpool lost ground in their hunt for a play-off spot as they fell to a 1-0 defeat to Kevin Nolan’s Notts County.
Centre-back Richard Duffy’s fourth goal of the campaign proved the match winner at Meadow Lane.
Luton Town confirmed their place in the top seven with an emphatic win at Accrington Stanley.
The scores were level the break but three unanswered goals from the Hatters in the second period made it a comfortable result.
Cheltenham Town secured their safety with a 1-0 win over relegation-threatened Hartlepool United.
The Monkey Hangers would have been relegated but for Carlisle United’s comeback against Newport County.
The Exiles led at the break thanks to Mickey Demetriou but Jabo Ibehre and Nicky Adams completed a Cumbrian comeback in the second period.
Leyton Orient’s match against Colchester United had to be completed behind closed doors due to fan protests at Brisbane Road.
The encounter was postponed for nearly two hours before Colchester were confirmed 3-1 winners.
John Akinde’s 26th goal of the season helped Barnet to back-to-back wins with victory over Grimsby.
Former Bristol City man Akinde is the division’s top scorer, with David Tutonda and Curtis Weston wrapping up the win, prior to Craig Disley’s consolation.
Elsewhere, Morecambe and Wycombe Wanderers drew at the Globe Arena while Cambridge United defeated Crawley Town.