Leeds slipped out of the automatic promotion places as 10-man Wigan pulled off a shock 2-1 win at Elland Road, boosting their survival chances in the process.
Marcelo Bielsa's side, looking to respond to Sheffield United's earlier 2-0 win over Nottingham Forest, looked on course for a routine victory when Patrick Bamford opened the scoring (17) just minutes after Cedric Kipre was sent off.
But Gavin Massey restored parity a minute before half-time and struck again in the second half (62) as Paul Cook's side defended in numbers and defied the odds to move five points clear of the relegation zone, as well as denting their hosts' top-two ambitions.
Having taking advantage of a Blades slip-up last weekend, Leeds trail second-placed United on goal difference with three games to go in the Championship.
Pablo Hernandez had missed the resulting penalty after Kipre's dismissal for handball but Bamford saved his blushes when he fired past Christian Walton to give the Whites the lead minutes later.
Both teams had chances, with on-loan Sheffield United forward Leon Clarke chipping the ball just wide after he intercepted a poor backpass from Gaetano Berardi, before Tyler Roberts saw a powerful volley cleared off the line by Latics midfielder Kal Naismith.
Massey drew the visitors level against the run of play when he got on the end of a Lee Evans flick on and scored past Kiko Casilla.
Half-time substitute Kemar Roofe wasted a brilliant chance to restore Leeds' advantage from close range in the 51st minute, before Mateusz Klich fired over six minutes later.
They proved to be costly misses as Massey hit his second to give Wigan a shock 62nd-minute lead after he headed home from Clarke's knockdown.
Wigan even went close to a third when Reece James clipped the top of the crossbar with a long-range effort after 72 minutes.
Walton saved brilliantly with his legs to keep out Bamford a minute later, before James fired wide with nine minutes to go after Wigan hit Leeds on the break.
Leeds cranked up the pressure late on and Walton saved at full-stretch to keep out Hernandez.
At the other end, James missed another great chance after dithering with his finish before he claimed to be fouled by Adam Forshaw in the area.
Leeds pressed for an equaliser in stoppage time but Wigan held on to move five points clear of the relegation zone.
Marcelo Bielsa: "There is no explanation why that happened today," Bielsa said. "Destiny gave us a red card, a penalty and 15 chances to score.
"We simply should have won that game today. The conditions were right there for us to win the game. It was a game that we had to win but it was a game that we did not deserve to win.
"I take full responsibility for the defeat for not planning the right path to make sure that we did get the win.
"I am sad at this defeat, but I am very motivated. We have had a good season, but it will mean nothing if we do not get promoted."
Paul Cook: "We are delighted to win and to get the three points," he said.
"When we had a man sent off and then they have the penalty, the first thought was 'how much can we keep them down to?'.
"You would expect Leeds to go on and win the game comfortably, but great credit to the players."