Former Swansea midfielder Jordi Gomez's late goal ended Neil Warnock's unbeaten start after Cardiff lost 1-0 at home to managerless Wigan.
The Bluebirds will feel hard done by as they dominated large spells of the game.
Gomez's 86th-minute strike moves Wigan to within one point from safety and ends their four-game winless run.
Sol Bamba and Anthony Pilkington squandered glorious opportunities to give their new boss his third win at the Welsh club.
Assistant manager Graham Barrow, development squad manager Peter Atherton and first-team coach Joe Parkinson took charge of Wigan following Gary Cadwell's departure on Tuesday.
The Latics are now just one place below Cardiff in the Sky Bet Championship table.
The home side controlled the opening stages of the game - Anthony Pilkington's header forced a routine save from Adam Bogdan in the seventh minute.
The pair faced each other again moments later as the Wigan stopper got down low to deny the Bluebirds' frontman from close-range.
The home side's pressure was relentless and they could have been ahead after 11 minutes, but Bamba's header was cleared off the line by Reece Burke.
Wigan have only conceded four goals in their last eight games and their resilience was tested again after Pilkington's dangerous-looking cross was vitally blocked by Burke.
The Latics' only shot on target in the first-half came through Yanic Wildschut when his tame shot rolled its way into Ben Amos' gloves.
Sean Morrison should have done better from a Peter Whittingham inswinging free-kick just before the break after he glanced his header wide of the post.
Wigan could have been in front within three minutes of the restart when Will Grigg's deflected shot drifted agonisingly wide of Amos' goal.
Jake Buxton had a good opportunity in the 50th minute for the Lancashire side, but he could not direct his header on target.
Cardiff replied to Wigan's two early second-half openings as Aron Gunnarsson's powerful drive was beaten away with one-hand by Bogdan from the edge of the area.
Warnock's men continued where they left off in the first half and wasted another glorious chance when Bamba somehow headed wide from close range.
The winner came after good work from David Perkins on the wing, who squared the ball to Gomez to tap home.
Cardiff could have snatched a late point but Bamba blasted the ball over the bar in the dying minutes of the game from six yards out.
The Bluebirds continued to throw the kitchen sink at Wigan, but the away side stayed resilient and held on for their first away win of the season.