Blues squeaked past Coleshill Town on penalties to reach the final of the Birmingham Senior Cup.
Nick Townsend sprang low to his left to save decisive spot-kick, from William Worthington, in a shoot-out.
Kamal Guthmy slotted in the first penalty when it reached sudden death and then Townsend broke the hearts of the plucky Midland Football League high-fliers.
After the sides failed to find the net in 120 minutes of hard-fought action, it all came down to who could hold their nerve and rely on technique from 12 yards at Pack Meadow.
Blues netted their opening three penalties via Liam Truslove, Mitch Hancox and James Fry before the first stop, from Townsend.
When Reece Brown then followed up by despatching the next penalty, Blues were 4-2 up.
Simeon Cobourne made it 4-3 and Charlee Adams had the chance to seal it for Blues, but Chris Jay made a fine save from his penalty.
Coleshill scored their fifth penalty to take it into sudden death, with Guthmy stepping up first to put the pressure on the hosts.
The whole night could have been a lot different - and easier for Blues - had Truslove not uncharacteristically steered a firm free header wide from a Josh Cogley cross in the 19th minute.
Denny Johnstone, on his return to Blues from loan at Cheltenham Town, brought out a smart save from Jay at his near post as Blues continued to threaten more in the first-half.
Fry blazed over after initially having a header blocked at a corner and, into the second-half, Johnstone couldn't quite adjust to get the ball from out under his feet at the front post after Cogley teed him up.
Viv Solomon-Otabor carried a major menace with his pace and dribbling, Brown showed his quality, but on a bobbly pitch neither side could trust a reliable bounce of the ball when in possession or knocking it about.
As the second-half wore on Coleshill came more and more into it in the attacking sense.
It was clear to see why they have gone 15 games unbeaten, winning 13, as they were sure of one another, well organised and then made more headway following the introduction of pacy substitute Cobourne.
Townsend had to be alert to save at his feet and, with nine minutes to go, Cobourne hit the post after forcing his way past a couple of challenges and deep into the Blues area.
Blues repelled a series of Coleshill corners before the semi-final reached extra-time. And at the onset, Townsend dived to his right to superbly push away a fierce drive from Coleshill's captain and prolific striker Shane Benjamin.
Blues tended to get bogged down the longer things went on and were unable to find that necessary knockout punch.
But they defended with great determination and not on any ceremony when required and eventually found a way to prevail via penalties, to set up a final showdown with either West Bromwich Albion or Nuneaton Town.
Blues: Townsend, Cogley, Hancox, Adams, Harding, Fry, Otabor (Guthmy 110), Truslove, Johnstone, Brown, Bell (Cooper 98). Not used: Kelly, Trueman.