Scunthorpe and Bristol City moved to within six points of Nottingham Forest at the top of League One as the leaders could only draw with Rotherham.
Colin Calderwood's side begun the day with a seven-point lead but allowed their rivals to make in-roads after drawing 1-1 at Millmoor.
Forest even fell behind when the hosts saw Will Hoskins (59) fire home, but Nathan Tyson's 88th minute strike ensured the spoils were shared.
With Yeovil drawing 0-0 at bottom club Leyton Orient, both Scunthorpe and Bristol City were able to close on Forest after securing home wins.
The Iron left it late to beat Northampton when Andy Crosby scored from the penalty spot with four minutes to go.
Gary Johnson's Robins, meanwhile, came from behind to move into joint second with a 3-1 victory over Gillingham.
Michael Flynn put The Gills ahead (15), but City completed a fine turnaround with Richard Keogh (29), Enoch Showunmi (77) and Scott Murray (90) on the scoresheet.
Tranmere Rovers moved into fourth following a 1-0 win at Brighton, with Chris Greenacre (20) scoring the all-important goal.
Oldham's chances of breaking into the play-off places were dashed despite winning, as Swansea also secured a 2-0 victory.
The Latics beat Bradford courtesy of a Chris Porter brace (79, 82), whilst Kenny Jackett's Swans triumphed at Port Vale in a dramatic conclusion that saw both Lee Trundle and Thomas Butler score in injury time.
Carlisle United are two points behind Oldham in eighth after beating Bournemouth 1-0 courtesy of a Karl Hawley penalty (5).
The performance of the day in League One came at Griffin Park with Dario Gradi's Crewe Alexandra side triumphing 4-0 over Brentford.
The visitors moved into ninth place in the league after goals from Luke Varney (pictured, 5, 63), Ben Rix (58) and David Vaughan (67).
Millwall managed to escape the relegation zone despite being held to a 2-2 draw at home to Doncaster Rovers.
The visitors twice took the lead in London through Jonathan Forte (16) and Jason Price (53), but a battling Millwall secured a point thanks to replies from Darren Byfield (40) and Chris Hackett (59).
Cheltenham's woes continued after a 1-0 defeat to Chesterfield left them joint bottom of League One, with Alan O'Hare's 48th minute goal condemning them to their 13th defeat of the season.
Blackpool moved into the top half of the table after beating Huddersfield Town 3-1 at Bloomfield Road.
Goals from Keigan Parker (26), Keith Southern (30) and Andy Morrell (60) overpowered The Terriers, but the Yorkshire side did claim a consolation when Gary Taylor-Fletcher scored on 48 minutes.
Click below for match summaries:
Blackpool 3-1 Huddersfield Town
Bournemouth 0-1 Carlisle United
Brentford 0-4 Crewe Alexandra
Brighton & Hove Albion 0-1 Tranmere Rovers
Bristol City 3-1 Gillingham
Chesterfield 1-0 Cheltenham Town
Leyton Orient 0-0 Yeovil Town
Millwall 2-2 Doncaster Rovers
Oldham Athletic 2-0 Bradford City
Port Vale 0-2 Swansea City
Rotherham United 1-1 Nottingham Forest
Scunthorpe United 1-0 Northampton Town