They were denied the PDL National Play-Off trophy after losing 4-2 to Leeds United Under-23s on penalties in the Final.
The Blues youngsters gave everything they could only to fall agonisingly short in the most jarring of circumstances.
The teams were locked at 0-0 after 120 minutes of absorbing action in front of a near 8,000 crowd.
And, overall, Blues were probably the better side and certainly shaded it in terms of the better chances created in normal and extra-time.
Olly McCoy was denied by goalkeeper Kamil Miazek twice late on before the extra period.
Then Josh Andrews was thwarted in a one-one-one after Remeao Hutton hit the crossbar.
In the end, the teams had to be separated by spot-kicks, and Blues had two of their penalties saved by the inspirational Miazek.
Matuesz Bogusz hit the post with the opening penalty and McCoy stuck his kick away down the middle to give Blues the edge.
After Pascal Struijk found the top corner, Geraldo Bajrami blasted home his penalty.
Ryan Edmondson was successful going to the top right corner before Joe Redmond stepped up.
Unfortunately Redmond’s low kick to the left was saved by Miazek, to make it all square at 2-2 after three penalties each.
Kun Mihaylov also went top right to give Leeds the advantage before Caolan Boyd-Munce had his penalty kept out, as he opted low to the left.
That gave Jack Clarke the chance to clinch it, which he duly did by firing hard and high past Jeacock.
The win gave Leeds the PDL North and Play-Off double; Blues had to settle for runners-up in both.
But it was no shame for the Development Squad, who again performed with pride, purpose and intelligent organisation.
Blues began the Final calmly and although Leeds had plenty of possession but Blues never allowed it to hurt them.
And they created the best two chances at goal in the first-half: in the 19th minute a raking low pass from Odin Bailey inside his own territory was missed by Aapo Halme and that allowed Adan George to gallop away.
His initial touch took him to the left of the area and his eventual shot was somewhat dragged and therefore easy for Miazek to save.
Leeds thought they had had a penalty earlier when Bajrami collided with Gaetano Berardi but the linesman's flag had long since gone up for offside.
Miazek was called into action again in first-half added-time after Blues took a quick free-kick high on the right.
Hutton sprinted forward and delivered a lovely cross on the run; Redmond, still up from an earlier set-piece, powered a fine header at goal which the 'keeper had to tip over.
It was decent, solid stuff from Blues, who locked down Leeds whilst also trying to capitalise when possession was turned over.
After the break, Leeds came out playing at tempo and moving the ball quicker than they had been. But Blues never got ruffled and as the Final went on, Leeds began to run out of ideas and the visitors finished the stronger.
In the 83rd minute, substitute McCoy squirmed his way clear from the left edge of the area but Miazek blocked with his feet – it was a big chance. Moments later McCoy again cut loose in a similar position but Leeds survived.
With five minutes left Blues had to reshuffle: the injured Ryan Burke – who had an excellent game – was replaced by Jude Bellingham, meaning Hutton shifted to left-back, Corey O’Keeffe dropped to right-back and Bailey to right wing.
But it didn’t alter their effectiveness and in extra-time, with Josh Andrews adding some extra oomph, Blues might have sealed it against a Leeds side who boasted seven players with first team experience.
In the 97th minute Hutton took a return pass from Andrews after finding him with a throw and struck a curving shot from the edge of the area that rebounded off the face of the crossbar.
And there was another let-off for Leeds five minutes later when Andrews shrugged off Halme and strode toward goal, only for Miazek to save his sidefoot attempt from close range.
In added-time Leeds then went close when Bogusz’s free-kick slammed off the post and the rebound was stuck away by Edmondson – only for the linesman’s flag to go up for offside.
The second period was extra-time was just as engaging and nervy as both teams summoned up a big last effort despite tiredness and the emotional energy expended.
McCoy ushered away a hurried close range effort from a corner by Hugo Diaz off the line before Blues went down the other end and seemed to have Andrews bundled over as he arrowed in on goal, but no penalty was forthcoming.
The last action before the shoot-out came when Leeds worked a shooting angle for Clarke Oduor on the left of the area, but Ryan Stirk produced a brave, brilliant block to protect his goal.
That was typical of the unselfish, team-orientated approach Blues showed throughout – and have done all season in fact – only for the just reward not to be forthcoming, in the harshest of fashions.
Leeds (4-1-4-1): Miazek, Berardi (Oduor 69), Struijk, Halme, Shackleton (Mihaylov 116), McCalmont (Diaz 87), Gotts, Bogusz, Clarke, Stevens, Edmondson. Subs not used: Rae, Nicell.
Blues (4-4-2): Jeacock, Hutton, Burke (Bellingham 85), Stirk, Bajrami, Redmond, O'Keeffe, Boyd-Munce, Bailey, George (Andrews 90), Hurst (McCoy 63). Subs not used: Bradley-Hurst, Forrest.