LEEDS UNITED'S automatic promotion destiny slipped back out of their own hands as a Gavin Massey double gave ten-man Wigan Athletic a 2-1 win at a stunned Elland Road.
Leeds were awarded a penalty in the 14th minute with Wigan also reduced to ten men when Cedric Kipre was shown a straight-red card for handling Patrick Bamford's shot on the line.
Pablo Hernandez's spot kick hit the post but United scored anyway just one minute later through a clinical finish from Bamford.
Yet Wigan equalised one minute before the break when Massey took advantage of slack defending to beat Kiko Casilla at his near post and Elland Road was left stunned when Massey scored what proved the winning goal following Leon Clarke's knockdown two minutes after the hour.
The defeat left Leeds third on goal difference behind Sheffield United who had brushed aside Nottingham Forest 2-0 in a lunch-time kick-off.
Leeds went close to taking the lead in the third minute when Jack Harrison's left flank cross flew across goal and missed Bamford but found Hernandez whose effort was headed off the line by Kipre.
Wigan then threatened six minutes later when a cross from the left presented an opening for Sheffield United loanee Leon Clarke who could only nod the ball past the left-hand post.
But the game exploded into life in the 14th minute when Bamford's attempts to turn home a strike from Hernandez led to Wigan defender Kipre handballing on the line and being shown a straight red card.
Hernandez stepped up to take the penalty but his effort hit the right hand post.
Yet just one minute later Leeds were in front thanks to a fantastic strike from Bamford who controlled Luke Ayling's right-flank delivery before firing home an unstoppable low shot into the bottom left corner.
Even then Leeds survived a moment of panic just five minutes later as Casilla's attempts to mop up a poor Gaetano Berardi back-pass gave Clarke the chance to round the Spaniard well outside his area but ultimately but a chipped effort over and wide.
Leeds came roaring back with Hernandez, Pontus Jansson - from a corner - and Kalvin Phillips all peppering the goal before a thunderous volley from Tyler Roberts was only kept out by fine headed clearance on the line from Kal Naismith.
But Wigan produced a sting in the tail in the 44th minute when Massey collected the ball out wide before advancing on Casilla who was beaten by a low finish at his near post.
Whites head coach Marcelo Bielsa reacted by bringing on top scorer Kemar Roofe and Adam Forshsaw with Roberts and Phillips taken off.
Roofe should have scored five minutes after the restart but the striker was unable to convert an opportunity from six yards out that keeper Christian Walton saved.
That came seconds after Luke Ayling's thunderous effort had been blocked with Hernandez then seeing another effort blocked after earlier firing well wide.
Mateusz Klich then powered a drive just over the crossbar from the edge of the box but Wigan were still causing problems and stunned Elland Road when taking the lead two minutes after the hour.
A cross into the box was knocked down by Clarke and Massey had the simple task of converting from close range.
Leeds hit back with a series of efforts but Massey continued to cause mayhem on the break and a free-kick won by the forward led to Reece James hitting the crossbar.
Leeds should have scored a minute later but Walton kept out Bamford's shot with his legs but Wigan still threatened on the break and a dangerous counter ended with James firing wide.
Hernandez was then denied by a fine save by Walton but Wigan should have put the game to bed in the 89th minute with James unable to finish a brilliant solo run and not awarded a penalty for what looked like a foul.
Leeds were given five minutes added time to find an equaliser but it never looked likely as United's automatic promotion destiny slipped back out of their hands.
Leeds United: Casilla, Alioski, Berardi, Jansson, Ayling, Phillips (Forshaw 46), Klich (Clarke 71), Roberts (Roofe 46), Harrison, Hernandez, Bamford. Subs not used: Peacock-Farrell, Dallas, Davis, Shackleton.
Wigan Athletic: Walton; Byrne, Dunkley, Kipre, Robinson; Morsy, James (Garner 90), Naismith, Evans, Massey (Powell 73), Clarke (Olsson 67). Subs not used: Evans, Gibson, Waindass, Roberts.
Referee: Scott Duncan.