Blues were denied at the death in this behind-closed-doors friendly at Reading's Hogwood Park training ground.
Kerim Mrabti put Blues in front in the 67th minute, in a second-half that the visitors controlled for the main part.
But an 87th minute equaliser put paid to hopes of victory.
Pep Clotet used this low key game to field a different side in either half (apart from Lee Camp) against a Royals team that was a mixture of first teamers and Under-23s.
Jake Clarke-Salter was thrown into the fray immediately, fresh from signing his loan deal on the morning of the match.
Jacques Maghoma got his first taste of pre-season action after extra time off following Africa Cup of Nations duty.
Michael Morrison played the opening half for Reading, his first outing since joining them on a free transfer after his Blues career came to an end.
In sweltering hot conditions, Blues survived an early scare when Reading got in behind and their centre-forward stuck the ball over the crossbar in the third minute from close range after being teed-up.
Blues, captained by Marc Roberts in the first period, responded with more of a threat as the half went on.
In the 38th minute Odin Bailey, who had earlier had a low shot saved, weaved his way across the front of the area before setting up Steve Seddon, advancing on the left. Seddon's chipped cross just eluded Isaac Vassell in the middle of the box.
After the ball was retrieved, Maghoma had blast at the front post but the 'keeper was behind the effort and blocked it away.
From the subsequent corner, Clarke-Slater went flying in and caused alarm for the 'keeper, the ball dropped for Seddon who hoisted it over the crossbar from a decent position.
Then Bailey fed Seddon storming in, he took the ball on his chest without breaking his run and struck a rising drive that only just cleared the woodwork.
Blues began the second period with purpose, and Crowley was immediately to the fore.
In the 47th minute a cross back in from Charlie Lakin popped out to Crowley and his goalbound shot was fortuitously deflected off target by a defender.
Blues were knitting some nice passes together in the final third and causing problems.
But in the 58th minute, new Reading signing Charlie Adam tried his luck from 25 yards with a swerving effort that Camp, at full stretch, tipped round.
Blues thought they had scored when a ball in from the right by Crowley went all the way through, as Lukas Jutkiewicz shaped to touch it near the six-yard line, but the Juke was flagged for offside.
Then, from a Jutkiewicz nod down after Craig Gardner's loft in, Crowley caught the ball full on the volley from just inside the area, only for the 'keeper to make a fine save, pushing the ball away.
A goal did come, though, from a neat move after a throw-in high on the right. Craig Gardner, Crowley and Mrabti exchanged quick passes and the latter was slipped into the area. Mrabti adjusted his body to create an angle and sent a low, left-footer through the 'keeper and into the bottom corner.
After Jutkiewicz pulled the ball back from the byline, Mrabti had a great chance to score again but he hit his shot into the ground, it reared up and a defender nodded it away from in front of the goal.
Reading had a good opportunity themselves as time ticked down, but an attacker on the stretch couldn't quite stick a right-wing cross past Camp.
But Blues continued to attack swiftly once gaining possession and when Harlee Dean broke up a raid on halfway, he kept on going after moving the line of the counter out right. Mrabti crossed low, Jutkiewicz let the ball run but Dean, coming onto it behind him, was unable to sweep it home.
After Craig Gardner went close with a swerving 25-yarder from a short corner, Reading stung Blues with a leveller.
It came after the defence momentarily stopped as Reading appealed for a penalty when a player went over as Dean got in to snuff him out; another forward was quick to bust onto the loose ball and veered to the right of Camp before finishing from a tight angle.
Blues (first-half, 3-4-1-2): Camp, Harding, Roberts, Clarke-Salter, O'Keeffe, Gary Gardner, Medina, Seddon, Bailey, Vassell, Maghoma.
Blues (second-half 3-4-1-2): Camp, Dacres-Cogley, Dean, Pedersen, Colin, Craig Gardner, Davis, Lakin, Mrabti, Crowley, Jutkiewicz.
Substitutes (not used): Stockdale, Trueman, Bellingham.