Leeds manager Marcelo Bielsa was left ruing a raft of missed chances as his side suffered what he called an "impossible" defeat at home to relegation-threatened Wigan.
Pablo Hernandez's unlucky 59th minute own-goal proved the difference as the Latics shocked title-chasers Leeds at Elland Road for the second season in a row.
And defeat for Bielsa's misfiring team saw them slip to second in the table as title-rivals West Brom won to leapfrog them at the summit.
The Baggies eased to a battling 2-0 victory at home to basement side Luton, but the Whites failed to overcome opponents at the opposite end of the table and now sit just three points clear of third-placed Fulham.
Leeds have won just two of their last nine matches and boss Bielsa couldn't fathom how his side lost, especially having created a hatful of chances.
"I have nothing new to say," admitted Bielsa. "This was an impossible match to lose, but we lost.
"The single question is why we lost a match which we had to win? We should have scored at least one of the 15 chances that we had.
"After 15 chances we had another ten situations where we didn't create danger. We didn't create danger in the box or inside the six-yard box.
"I can't say whether our goalkeeper (Kiko Casilla) should have done better (for the goal), I'd need to see it again.
"But in 40 minutes we had 15 chances and in every match we have (created) more chances than our opponent.'
Asked whether he was frustrated with defeat and West Brom going top, the Argentine snapped: "No! There is nothing that makes me feel frustrated.
"Let's imagine if West Brom lose today, well then we'd still be frustrated with the result. But I didn't see our players at a low level, we attacked in the right way.
"There was one team which tried to attack and I didn't see a problem with our defence. We played the way we had to play, but it's difficult to think we would not score.
"We tried to remain focused in defence, but what I imagined what would happen didn't happen. It was difficult to think we wouldn't score, but the opposite two things happened.
"It's clear that the responsibility is on me as manager. If the team doesn't do what I ask, then okay.
"But if the team does everything I ask then it's my responsibility (if we lose). But we are talking about a team who are second in the table.
"You have to be a self-critic, which is deserving (after the result)."
Jubilant Wigan boss Paul Cook has renewed hope his relegation-threatened side can avoid the drop.
Back-to-back victories have lifted the Latics to within two points of safety.
"I'm delighted for the players," praised Cook.
"We were 1-0 down at half-time in midweek (at home to Sheffield Wednesday), so to have finished the week with six points is brilliant. We showed desire, determination and a real spirit.
"Last year's win over them (Leeds) was freakish, it a was million to one shot last season. Leeds took control (today) but I thought we defended manfully.
"You know you're going to be under pressure here, but we filled the gaps really well.
"It (victory) gives us a great opportunity to stay up. If we keep winning games then we won't have a problem."
Cook's side were forced to weather a barrage of pressure, but their perseverance paid off as the clinched a memorable victory on their travels.
"I've said before, we need to keep winning games to stay up," stressed Cook. "I've said that all along.
"We've managed to bring three lads in that will help us. It's going to be a really good challenge to stay up, but if we play like that then we'll give ourselves a good chance.
"We had to defend well, but we had chances as well. There's a big challenge ahead, but it's one we're looking forward to."