Marino Keith's seventh goal in six matches gave The Pilgrims an improbable win at the JJB Stadium, as Paul Jewell's Latics saw their lead at the top of the table reduced to nine points.
Crewe Alexandra boosted their chances of automatic promotion after finally overcoming Stockport County 1-0 at Gresty Road.
Rodney Jack's winner with 13 minutes left saved the Railwaymen's blushes to keep them second, though Cardiff City now have two matches in hand to catch Crewe for the second automatic promotion place.
Bristol City moved above Oldham Athletic into fourth place with a 2-0 victory over Barnsley at Ashton Gate.
Scott Murray put The Robins in front after intercepting a poor Tykes back-pass to round the goalkeeper and score after six minutes.
Christian Roberts sealed the win for Danny Wilson's men just after the hour mark after converting a Mickey Bell cross to make it 2-0.
Oldham Athletic drop to fifth after being held to a 1-1 draw by struggling Port Vale at Boundary Park.
David Eyres gave The Latics a 1-0 lead in the first half before Michael Cummings equalised eight minutes later, as The Valiants earned a share of the points to push them away from the Division Two drop zone.
Queens Park Rangers remain three points clear in the final play-off spot after a big 3-1 away win at Blackpool.
A hat-trick by Richard Langley gave the West London club all three points as The Seasiders had to settle for a late Scott Taylor consolation in the last minute.
Tranmere Rovers kept pace with QPR with a 2-1 victory over struggling Chesterfield at Prenton Park.
New loan signing Iain Anderson gave Rovers a 1-0 half-time lead before Canadian international Iain Hume made it two, six minutes after the break.
David Reeves got a goal back for The Spireites with 12 minutes left but it was not enough to earn a share of the points in The Wirral.
Colchester United moved up two places to 11th with a 1-0 win over Swindon Town at Layer Road.
Kemal Izzet scored the winner three minutes before the hour mark as The U's went above their Wiltshire opponents in the table.
Brentford got three second-half goals from Matthew Somner, Martin Rowlands and Stephen Hunt to defeat relegation-threatened Northampton Town 3-0 at Griffin Park.
Notts County came from behind to beat lowly Huddersfield Town 3-2 at Meadow Lane.
Andy Booth had put the cash-strapped Terriers 1-0 up with a header before Paul Heffernan equalised with a header of his own.
Danny Schofield put the visitors back in front with a swinging free-kick eight minutes before the break.
However, the match turned late in the second half with two penalties from Mark Stallard, including the winner in injury time to extinguish Huddersfield's hopes of earning a point late on.
Peterborough United pulled themselves away from the relegation zone after demolishing Mansfield Town 5-1 at Field Mill.
The Stags' reputation of being the poorest defensive side in league football again became apparent as Barry Fry's Posh blasted their hosts on Saturday.
Goals by Simon Rea, Leon McKenzie, Ian Hendon, Andy Clarke and Andrew Fotiadis were more than enough to give The Posh the three points as Mansfield got a consolation goal from the penalty spot through Wayne Corden.
Click below for match stats:
Division Two
Blackpool 1-3 Queens Park Rangers
Brentford 3-0 Northampton Town
Bristol City 2-0 Barnsley
Colchester United 1-0 Swindon Town
Crewe Alexandra 1-0 Stockport County
Mansfield Town 1-5 Peterborough United
Notts County 3-2 Huddersfield Town
Oldham Athletic 1-1 Port Vale
Tranmere Rovers 2-1 Chesterfield
Wigan Athletic 0-1 Plymouth Argyle
Click here for an updated Division Two table.
