Coventry's winless run extended to nine matches after they shared a 1-1 draw with Preston.
If Sheffield Wednesday fail to beat city rivals United on Sunday, Chris Coleman's Sky Blue will finally be mathematically clear from relegation as their season grinds towards an unsatisfactory conclusion.
Coventry were dangerous on the break in the opening period and took the lead through Freddie Eastwood.
North End then proceeded to enjoy the better of the half and Callum Davidson equalised from the penalty spot.
It was a game of few chances after half-time, although livewire Preston winger Danny Mayor was a constant threat.
It was Mayor who fashioned the half's best opportunity 10 minutes from time when Jon Parkin was thwarted by Coventry keeper Kieran Westwood.
Liam Chilvers partnered Sean St Ledger at the heart of the Preston defence, with on-loan centre back Elliot Ward ineligible to play against his parent club and Youl Mawene away on compassionate leave, while winger Ross Wallace returned from a two-game ban.
Eastwood recovered from a back injury to replace Freddie Sears in attack for Coventry, while winger Michael McIndoe shook off a similar complaint to make the starting line-up.
And McIndoe came close to opening the scoring in the eighth minute when he forced an excellent fingertip save from Andy Lonergan after the Sky Blues had broken sharply from a North End corner.
The game's opening moments were largely subdued but the contest sprung into life in the 18th minute.
Some intricate play from Wallace released Keith Treacy who cut back onto his left and forced Westwood in to his first save of the afternoon.
From that Preston attack Coventry broke, with McIndoe involved once more, and his pass from the edge of the area found Eastwood who swept past Lonergan right footed.
Mayor's pace was keeping Preston on the front foot, but a last ditch block from North End captain Callum Davidson prevented McIndoe ending yet another counter attack in fruitful fashion.
Just after the half hour Wallace delivered a dangerous free kick into the Coventry box, which Parkin swung airily at before Westwood tipped to safety.
Moments later, a fizzed Mayor cross just evaded Parkin and Chilvers volleyed over from a Wallace corner.
The pressure finally told in the 37th minute after Richard Wood felled the marauding Parkin in the area and Davidson drilled the spot kick into the corner past Westwood's dive.
Coventry hit back and Lonergan did well to thwart both Morrison and McIndoe before the interval.
Moments after half-time Davidson came close to a second when he arched a shot on his weaker right-foot narrowly past the upright from 25 yards.
In the 51st minute Parkin headed inches over Matthew James' cross following some smart interplay with Treacy.
Chances were at a premium, but Mayor continued to be a menace for Coventry full-back Stephen Wright and in the 79th minute his cross found Parkin who chested down before volleying goalwards, but Westwood saved magnificently.
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