They failed to build on an early goal and then allowed Wednesday to regroup and register their first win in nine attempts in front of the Championship's highest attendance of the season.
Coventry defender Elliott Ward scored his fourth goal in three games against Wolves to boost his side's survival hopes.
But Sylvan Ebanks-Blake's penalty in the 52nd minute gave the visitors the point they needed to stay in touch with sixth-placed Crystal Palace.
Stoke City moved a step nearer promotion to the Premier League with a narrow win over Colchester in what was the last ever game to be staged at Layer Road.
The hosts were looking to end an era with a rare victory, but they remained rooted to the bottom of the Championship tale following yet another defeat.
The game did not really mark the occasion - Layer Road has been hosting football for 101 years - but that won't worry Stoke, who came up with the winner in first-half stoppage time.
Richard Cresswell was the marksman from close range. Rory Delap hurled one of his trademark long throws into the penalty area and, although keeper Dean Gerken managed to keep out Cresswell's initial header, Liam Lawrence rifled the rebound back into the six-yard box for Cresswell to divert home, the ball seeming to come off his knee.
Hull City kept alive their hopes of automatic promotion after sealing a 2-1 victory against a frustrated Crystal Palace side at the KC Stadium.
The scores were level at half-time as Fraizer Campbell gave City the lead with Scott Sinclair equalising for the visitors, then late on Ian Ashbee stole all three points for his side with a dramatic winner.
Sheffield United go into the final game of the season with their hopes of a return to the Premier League still alive.
Two goals from Gary Speed sank Bristol City as United chalked up their eighth win in ten games to put them within reach of a top-six finish.
Barnsley sealed their Championship survival with a week to spare as they finished off their Oakwell season in style.
First-half goals from Jamal Campbell-Ryce and Lewin Nyatanga and a late header from Jon Macken were enough to give the Tykes a 3-0 win over Charlton .
Plymouth Argyle stormed to a comfortable 3-0 win over a somewhat flat Blackpool side, and Norwich recorded an identical win over QPR .
Burnley played out a 3-3 draw with the FA Cup finalists Cardiff , while Preston were held 2-2 by Ipswich at Deepdale.
Hereford won promotion to League Two thanks to a 3-0 win at Brentford.