Gary Haines reports
Charlton were denied a happy return to the Championship by Nikola Zigic on Saturday.
The big Serbian fired home in the final added minute at St Andrews to cancel out Leon Cort's late opener for the visitors.
It was cruel fortune on the Londoners who warranted all three points from a stellar effort in the West Midlands.
And they looked like they would return home with a full complement after Cort forced home a header eight minutes from time.
It was his first goal for the club, and timely to the extreme, but Zigic then found space in an otherwise watertight Addicks backline at the death and smashed home a low shot.
The scenes at the final whistle resembled a home win as the hosts celebrated wildly, surely through relief more than anything else. Conversely. it must have felt like a loss for the visitors, who must remember how well they played here.
Brum were second best for most of this game with the Addicks creating chance after chance but crucially failing to convert.
The opening period was near perfect for the visitors with the only thing missing, crucially, a goal.
Johnnie Jackson saw an early free-kick deflect just wide and then headed the subsequent corner over.
New England keeper Jack Butland foiled Bradley Wright-Phillips from a narrow angle and after the striker just missed a tempting cross from the left, Yann Kermorgant could only turn the ball over.
The best chance of all arrived shortly after the half hour mark as Rhoys Wiggins bombed down the left and centred for Jackson to head over again.
Talk at the interval was about those presentable chances with the Addicks quicker and sharper in all areas of the pitch, while Lee Clark was left to rouse the lethargic hosts from their opening period slump.
Blues started the second half with more purpose but it was Jackson again who stretched to head a cross wide after another well-constructed move
Ben Hamer was equal to the home sides efforts and at the other end Cort converted after a sequence of corners to give Charlton a lead they thoroughly merited.
But they couldnt quite get overt the line as Zigic, on for the final four minutes, made his considerable presence felt.
The big team news saw Bradley Pritchard handed a start on the right hand side as Chris Powell pitched in the same side that beat Fulham in their final friendly last weekend.
The midfielder got the nod to join skipper Jackson, Dale Stephens and Danny Hollands, who played the full two hours in the Capital Cup clash with Leyton Orient in midweek, in the middle of the park.
Ben Hamer and centre-back Leon Cort were the other two that played the full game against the Os and the backline is completed by Chris Solly, whose Addicks debut came in the clubs last Championship fixture, Michael Morrison and Wiggins.
Last seasons top-scorer Wright-Phillips was partnered by Kermorgant up front.
An increased allowance of substitutes meant two extra bodies on board with all three summer signings, Lawrie Wilson, Jordan Cook and Salim Kerkar waiting in the wings. John Sullivan, Matt Taylor, Danny Green and Michael Smith made up the reserve ranks.
The hosts handed a debut to former Addick Darren Ambrose, whose Charlton debut eight seasons ago at Sunderland ended early after he received a straight red card.
There was also a first start for highly-rated keeper Butland, three days after he started for England, and a couple of weeks after he represented Great Britain in the London Olympics.
In the middle of the park Hayden Mullins and West Ham United loanee Ravel Morrison started together for the first time with Ambrose and the dangerous Chris Burke on the left and right respectively.
There was no Stephen Carr at the back so Will Packwood deputised. Peter Lovenkrands played off Marlon King up front.
The Addicks were all in red on opening day while chants of Englands number one greeted Butland as he took his place between the posts.
Ambrose was roundly booed when he got his first touch and subsequent other interventions and the first shot of the day came from Lovenkrands as he collected a David Murphy cross and span sharply with Hamer saving routinely.
After a Curtis Davies foul on Wright-Phillips the Addicks almost grabbed a third minute lead from the subsequent free-kick.
Jackson got the nod over Kermorgant and his curler deflected off the top of the wall and Butland was scrambling across as the ball flew behind for a corner.
Butland could thus say his first touch as a Blues player was not picking the ball out of the back of his net, although his first goal-kick came after Jackson leapt to head Stephens flag-kick just over.
It was a promising start for the visitors and it was all about the Bradleys in the fifth minute as a Pritchard pass sent Wright-Phillips away right of centre.
He outmuscled Steven Caldwell impressively inside the box, but was eventually foiled from a narrow angle by Butlands block.
At the other end Pritchard got a crucial flick header away from a lurking Ambrose, and some superb skill from Kermorgant outwitted his marker moments later, although Wright-Phillips was just ushered out as the ball was filtered through.
The Addicks went desperately close again in the 13th minute as a terrific cross from Jackson just eluded Wright-Phillips and Kermorgant, arriving behind, had to time to adjust and could only turn the ball over.
The visitors could be more than satisfied with their start but a warming shot was fired as Lovenkrands sent a bouncing effort just wide as the clock reached 18.
Ambroses free-kick two minutes later had plenty of pace, but was expertly pouched by Hamer.
Charlton were continuing to create chances, however, and Hollands picked out Pritchard on the right and his tempting centre was headed over by Wright-Phillips midway through the half.
Ambroses audacious volley self-teed up posed more problems to the fans after sailing horribly high and wide, and Hollands volley was not much better soon afterwards up at the other end.
Lovenkrands jinked one way and then the next before Hamer denied the Dane but again Charlton responded with a great chance.
Wiggins was the creator in the 33rd minute, bombing down the left and carving out a superb cross for Jackson who headed over the bar.
It was another big moment for the visitors that went awry with the chances really starting to stack up.
Brum broke dangerously as Burke outmuscled Wiggins, but his clipped cross was clutched by Hamer.
And after a Stephens corner Morrison found space round the back but his header back across goal could not find a red head in the middle.
Namesake Ravel Morrison, playing very deep in the opening half, then broke forward for the first time five minutes before the interval but his low shot sailed wide of the left post.
Sollys low cross was controlled by Wright-Phillips who teed up Kermorgant to warm the gloves of Butland.
King got no direction on a home corner in the last knockings of the half but few could argue that the visitors had not been the better side in the opening period.
Kermorgant was booked for a sliding challenge on Ambrose four minutes after the restart and Burke cut inside and curled an effort over the bar soon afterwards.
Morrison slid in to make a perfectly-timed block on King as the striker moved through and there was more purpose in Birminghams play at the start of the half.
Wright-Phillips pull-back couldnt find a red shirt after Kermorgants flick found him on the left side of the box, and Jackson was again close for the visitors a minute shy of the hour mark.
After a corner was half-cleared, Kermorgant released Pritchard on the right and his cross was headed over by Jackson, emerging through a sea of players and on the stretch.
The hosts then made a double change as Packwood and Ravel Morrison made way for former Addick Jonathan Spector and Nathan Redmond.
There was a half chance for the hosts as King span sharply but he could only fire straight at Hamer.
A strong, but fair, challenge from Solly on Murphy saw the home left-back clatter against the advertising hoarding behind the goal.
After a loose header from Ambrose fell kindly to Jackson on 76 minutes, the skippers low shot was creeping into the bottom corner before Butland saved low to his left.
At the other end Redmond sliced wide from the left side of the box after a King shot was blocked and dropped into his path.
The busy Wright-Phillips made way for Cook soon afterwards and the newcomer made his presence felt with a string sliding challenge on Ambrose moments after his introduction.
Play continued with Clark far from happy on the home touchline and his mood darkened eight minutes from time as the visitors grabbed a deserved lead.
After Jacksons corner was returned back to him, the skipper clipped the ball to the far post where Cook nodded back across goal.
Kermorgant then headed down towards the far post where Cort propelled himself to nod home from close range.
The 1,637 strong Addicks fans immediately behind the goal erupted, as did the home bench, with Clark predictably sending on the towering Zigic for the closing stages.
Powell responded by sending on Taylor for Jackson with Burke crashing shots wide either side of the changes.
There were four added minutes to negotiate for the Addicks, who were helped by a couple of fouls conceded by the cumbersome Zigic.
But the big man would have the final say with just seconds remaining.
After a hopeful ball bounced favourably across the box, he took advantage, jinking into space and dispatching a clinical shot into the bottom left corner of the net.
There was scarcely time to restart with the natives those who were left celebrating wildly after the Serbian played his get out of jail card.
It was a harsh lesson for the Addicks, very harsh. Welcome to the new season. Welcome to the Championship.
Charlton Athletic: Hamer; Solly, Wiggins, Morrison, Cort; Pritchard, Hollands, Stephens, Jackson (Taylor 89); Kermorgant, Wright-Phillips (Cook 77).
Subs (not used): Sullivan, Wilson, Kerkar, Green, Smith.
Goals: Cort 82
Booked: Kermorgant 49 (foul on Ambrose)
Birmingham City: Butland; Packwood (Spector 64), Murphy, Caldwell, Davies; Burke, Mullins, Morrison (Redmond 64), Ambrose; Lovenkrands (Zigic 86), King.
Subs (not used): Doyle, Ibanez, Elliott, Rooney.
Ref: G Sutton
Att: 18,210 (1,637 Charlton)