Gary McSheffrey, one of Leeds' less vaunted loan signings under the recently sacked Simon Grayson, converted his second penalty of the night in stoppage time to give Coventry a deserved victory and renewed hope of avoiding third-tier football for the first time since 1964.
Leeds, supposedly fighting for a play-off place, showed scant ambition even after Ross McCormack's swift riposte to McSheffrey's early goal. Their second loss in four days under caretaker manager Neil Redfearn was sealed after Aidy White brought down the on-loan Manchester City striker Alex Nimely, as Coventry celebrated their ascent from bottom spot.
Redfearn, for whom Saturday's visit of Doncaster will be the last match in charge unless Bates makes him "permanent", did not mince his words about the poverty of Leeds' performance. "We were poor from minute one," he said, going on to admit he told his players some "home truths". "We conceded [a winner] against Brighton after 90 minutes and we've done it again. It's unprofessional. We didn't compete well enough and we carried too many players."
His Coventry counterpart, Andy Thorn, described their fourth home win in five games as "a man's performance". After praising the composure of McSheffrey and the menace of Nimely, who won both spot-kicks, he added: "We were adrift at the bottom not long ago and people wrote us off. But that made us really strong as a group, and there's still 45 points to play for."
The likelihood of Portsmouth forfeiting points as a result of going into administration gives Coventry an added incentive. They are unlikely to encounter many sides as obliging as Leeds, whose bid to re-establish momentum by firing Grayson seems to have backfired.
McSheffrey put Coventry ahead after Danny Pugh felled Nimely midway through the first half. McCormack stroked the equaliser after being fed by Adam Clayton, but Leeds' shoulders sagged visibly after their 3,300 followers reacted angrily to Redfearn's substitution of McCormack. Nimely twisted into a shooting position before being halted illegally, allowing McSheffrey to beat Andy Lonergan a second time.
Coventry City (4-4-2): Murphy; Christie, Keogh, Cranie, Clarke; Baker, Deegan, Norwood, McSheffrey; Nimely, Platt. Substitutes not used Dunn (gk), Eastwood, Bigirimana, Ruffels, Willis.
Leeds United (4-4-2): Lonergan; Smith (O'Brien, 74), Lees, O'Dea, Pugh; Snodgrass, Delph (Brown, 62), Clayton, White; McCormack (Nunez, 83), Becchio. Substitutes not used Taylor (gk), Townsend.
Referee P Miller (Bedfordshire).