Clayton Donaldson’s brace wasn’t enough as visiting Preston battled back to earn a point with two late goals.
Donaldson took his recent goal tally to four in as many games – his 10th and 11th of the season – with predatory strikes towards the start of each half.
Gary Rowett’s men at that point seemed in complete control before the visitors mounted a spirited late response.
Alan Browne reduced the deficit to one on 73 minutes, making for a nervy finish.
And as Blues tried to hang on, Preston’s determination was rewarded, Greg Cunningham restoring parity with just one minute of normal time remaining.
Diego Fabbrini came in for his first start in five games and was clearly in a mood to impress, bringing the game to life with several forceful jinking runs early on.
The Italian played an instrumental role in the attack that saw Blues edge in front on 13 minutes, showing good reactions and neat control to latch onto right-back Paul Caddis’ low cross into the box.
Fabbrini had seen an earlier shot from a similar position blocked but this time he got his effort away quicker, Preston keeper Anders Lindegaard only able to parry it away into the path of a grateful Donaldson who stroked the ball confidently into the bottom corner.
The visitors came close to levelling within three minutes, Joe Garner lashing in a 20-yard half-volley at the second attempt after the ball had rebounded to him, his shot whistling only narrowly past the post.
Paul Gallagher had an opportunity from a similar distance a few minutes later but that one never looked like troubling Tomasz Kuszczak, who had been recalled in favour of Adam Legzdins between the Blues posts.
Kuszczak was called into action on 31 minutes though as he sprung to his left to turn aside Eoin Doyle’s far-post header after Gallagher’s dangerous in-swinging cross.
Blues responded straightaway with a sharp counter-attack, Jacques Maghoma cutting inside from the left and crashing in a shot that was deflected over, the winger adamant that the ball had struck an arm.
Soon afterwards an aerial challenge between Maikel Kieftenbeld and Garner left the Blues man grounded and requiring treatment, but it was to no avail as the Dutchman departed the action soon afterwards to be replaced by Stephen Gleeson.
Michael Morrison, up for a free-kick, caused the Preston defence some problems late in the first-half.
The skipper’s persistence saw him get to the byline and crash the ball across the six-yard box – it just evaded fellow defender Jonathan Grounds as he looked to apply the vital touch.
Preston had a couple of late first-half openings, Adam Reach’s pot-shot from distance bouncing just wide, while Garner did test the reflexes of Kuszczak with an effort from the edge of the area, but the Blues custodian was equal to it.
The visitors were forced into their second substitution of the game at half-time – Marnick Vermijl having limped out of the action earlier in proceedings – as goalkeeper Lindegaard, who’d needed treatment in the first-half, was unable to continue and replaced by Chris Kirkland.
The former England and Liverpool keeper found David Cotterill’s free-kick too hot to handle as a quiet second-half got the spark it needed on 59 minutes.
Maghoma’s purposeful run brought a foul from Bailey Wright, the Preston man earning a yellow card for his troubles, 30 yards from goal.
Cotterill’s swerving outside of the foot effort had Kirkland scrambling down to his left and he was only able to push the ball out, the poaching Donaldson sticking out a leg and directing it back past the North End keeper and into the top corner.
The visitors threatened a rapid response, substitute Paul Huntington’s towering header brought an excellent fingertip save from Kuszczak.
The same Preston man presented Blues with a free-kick opportunity in a dangerous area 25 yards out, hauling down Donaldson, but this time Cotterill was unable to keep his curling effort down.
Just as Blues looked to be coasting to victory, Preston grabbed a lifeline on 73 minutes.
Skipper Tom Clarke led by example by racing to the byline and producing an inch-perfect pull-back to Alan Browne who fired past Kuszczak from close range.
Rowett’s response was to make his first unenforced change of the evening, Fabbrini leaving the field to a good reception from the home fans after a decent night’s work, with Kyle Laffery taking his place.
Buoyed by their goal, Preston mounted some concerted pressure and it eventually told in the 89th minute as Simon Grayson’s men grabbed a late equaliser.
Paul Gallagher’s corner caused chaotic scenes inside the Blues six-yard box, Cunningham hitting the post, and then sub Jermaine Beckford also denied by the woodwork before the ball bounced back kindly for Cunningham to fire past Kuszczak.
Preston even went in search of a winner, Garner’s 20-yard shot on target but comfortably claimed by Kuszczak.
The draw leaves Blues in ninth and now mathematically certain to be facing another season of Championship football.