An undermanned Birmingham could not repeat their Carling Cup heroics despite a gallant effort against a Bolton outfit who would be beaming after reaching the final four for the first time in 11 years.
It was a high-octane, absorbing battle with the Trotters grabbing the ascendency just after the 20-minute mark through Johan Elmander before Cameron Jerome restored parity for the home side just before the break.
The second half was full of excitement as both sides went after goals and it was Kevin Davies' 66th minute penalty which put the visitors ahead before Birmingham hit back for a second time via a Kevin Phillips special.
But substitute Lee Chung-yong supplied the winner in the 90th minute, sending Owen Coyle and his men into the next phase of the famous cup competition.
Venue: St Andrew's, Birmingham Crowd: 23,699 Referee: Phil Dowd Yellow cards:BC - nil BW - Gretar Steinsson 20, Kevin Davies 81'
With 10 regular first team players out, Alex McLeish took a second string Blues line-up into the clash but they began brightly despite their shortcomings in regard to player personnel.
Curtis Davies flicked a header goalward from a Sebastian Larsson free-kick in 12th minute which was Birmingham's best early chance before the visitors came into the contest.
Bolton were beginning to produce positive build-ups with Martin Petrov and Stuart Holden causing some bother for the home side but it was Johan Elmander who broke the deadlock in the 21st minute.
GOAL A long ball was bounced around off a few heads before Fabrice Muamba won it in the air, putting it towards Ivan Klasnic who played a neat little flick with the outside of his left foot into the path of the Swede who had beaten off his marker and managed to hammer home past Ben Foster with an unstoppable left-footed shot for his first goal in 10 matches.
Birmingham made two early changes with Martin Jiranek unable to go on after copping a heavy knock to his ankle and Barry Ferguson succumbing to a bout of broken ribs with Liam Ridgewell and teenager Nathan Redmond their replacements before the match became fairly hectic as both sides went on the attack.
GOAL Seven minutes before the break, the Blues hit back when Cameron Jerome won a header from a long ball which was poorly cleared by Trotters centre-half David Wheater. Jerome picked up the scraps and sent a well-placed half-volley from just inside the area past Jussi Jaaskelainen who had perhaps given too much leeway to the far post - the ball sneaking in at the near post for the striker's fifth of the season.
The equaliser gave plenty of voice to the St Andrew's faithful who got more involved when there was a shout for handball in the Bolton penalty area but referee Phil Dowd paid a free-kick to the home side for a push on Curtis Davies.
Bolton needed some creativity and guile up front as their direct, long-ball game was not quite working as down the other end Jaaskelainen saved the day in the 58th minute when Jerome found space and tried to round the Finn but he managed to get a toe in on the edge of the area to force a corner.
Owen Coyle introduced South Korea international Lee Chung-yong and midfielder Mark Davies just after the hour-mark as he chased the game and it had an immediate effect, although for a different reason to what he would have hoped, when Lee cleared Kevin Phillips' header from a Larsson corner off the line.
The Trotters thought they had scored when skipper Kevin Davies slotted home from close range after being found by Elmander in the 65th minute but the flag was up for off-side.
However, less than a minute later, Davies was awarded a penalty when he was brought down by his namesake who produced a clumsy challenge in the area. GOAL The Bolton striker stepped up and delivered for his club, putting the spot kick straight down the middle with Foster diving to his left to make it 2-1.
Bolton were looking far more dangerous after their second goal with plenty of ball going through Lee on the right flank but Birmingham kept coming hard and almost leveled with 20 minutes remaining when Phillips weaved his way through a host of defenders before angling his shot across goal but Jaaskelainen made a finger-tipped save to push into the far post, saving the day again.
Foster came up with two vital saves down the other end, the second a well-struck volley by Elmander, and it proved decisive when the home side leveled in the 80th minute thanks to a superb goal by veteran Phillips.
GOAL The ball dropped near the pint-sized striker after a long Davies header from defence was deflected on by Redmond and he used his goal sense and nous to turn on the edge of the area and throw his right boot at the ball. Despite being under extreme duress, Phillips managed to guide his looping shot over Jaaskelainen and into the back of the net, sending the home fans into raptures.
We were all set for a grandstand finish and it came from a Bolton point of view when Lee put his side 3-2 up in the final minute of regular time. GOAL Davies won a header in the area which fell to the substitute who had ghosted into the area and finished with a simple header from the edge of the six-yard box to send the Trotters into the final four.
Birmingham Ben Foster (gk) - David Murphy (Derbyshire 83'), Stuart Parnaby, Martin Jiranek (Ridgewell 28'), Curtis Davies - Barry Ferguson (Redmond 29'), Sebastian Larsson, Jean Beausejour, Jordon Mutch - Kevin Phillips, Cameron Jerome
Bolton Jussi Jasskelainen (gk) - Gretar Steinsson, Gary Cahill, David Wheater, Paul Robinson - Martin Petrov (Taylor 90+1'), Stuart Holden, Fabrice Muamba (M.Davies 61') - Ivan Klasnic (Lee 61'), Johan Elmander, Kevin Davies