Carlisle's lead is down to five points in League Two, while Grimsby dropped out of the automatic promotion places.
The Cumbrians, still well on course for promotion, had to come from behind at The Memorial Stadium to claim a 1-1 draw with Bristol Rovers.
Craig Disley (55) had put Rovers ahead, but Simon Hackney (pictured) made sure of a point for Carlisle with 15 minutes left.
Grimsby began the game in second, but they could only play out a 1-1 draw with Shrewsbury at Blundell Park.
Sagi Burton (27) put the visitors ahead, but they could not hang on as Marc Goodfellow (64) fired home a second half penalty.
Northampton climb into second after a 1-0 success at Darlington, with Scott McGleish's (70) late goal enough for The Cobblers.
Leyton Orient find themselves in the top three, after they claimed maximum points at Mansfield - with again just one goal in it as Matt Lockwood slotted him a penalty with just 15 minutes left.
Wycombe remain fifth despite going down 1-0 at Chester, with Stuart Drummond grabbing the winner on the hour at The Deva Stadium.
Cheltenham came from behind to claim victory at bottom of the table Torquay - who are now six points adrift of safety.
Lee Thorpe (26) put The Gulls ahead, but Damian Spencer (60) and Kayode Odejayi (70) sealed the win for The Robins.
Peterborough maintain their hold on the last play-off spot despite going down to a 1-0 loss to Boston United, whose winner came from Jamie Clarke on 69 minutes.
Lincoln missed the chance to move above The Posh as they could only draw 1-1 with Bury at Sincil Bank.
Marc Pugh put Bury ahead, but Lee Frecklington grabbed a late leveller for The Red Imps.
At the bottom, Rushden looked as they would climb out of the relegation zone but they conceded a last minute equaliser against Rochdale.
Drewe Broughton (55) put The Diamonds ahead only for Chris Dagnall to fire home in the last minute.
Stockport put a two-point gap between them as they beat Wrexham 2-1.
Goals from Ashley Williams (6) and Micheal Raynes (42) sandwiched a Simon Spender (38) effort to give The Hatters victory.
Stockport now climb above Barnet - after they went down 2-0 at Oxford with Tcham N'Toya grabbing a brace at The Kassam Stadium.
Finally Notts County and Macclesfield played out a 1-1 draw at Meadow Lane.
Mike Edwards had scored for The Magpies on the stroke of half time, but Town sealed a point thanks to a last-minute penalty from Paul Harsley.
Click below for match summaries:
Bristol Rovers 1-1 Carlisle
Chester 1-0 Wycombe
Darlington 0-1 Northampton
Grimsby 1-1 Shrewsbury
Lincoln 1-1 Bury
Mansfield 0-1 Leyton Orient
Notts County 1-1 Macclesfield
Oxford 2-0 Barnet
Peterborough 0-1 Boston
Rushden & Diamonds 1-1 Rochdale
Stockport 2-1 Wrexham
Torquay 1-2 Cheltenham