It was a victory born of farcical misfortune and thoughtful preparation, a shock that, on the basis of the 90 minutes, actually wasn't that shocking but nevertheless ranked as the biggest upset in an English showpiece since Everton beat Manchester United in the 1995 FA Cup final.
It was Birmingham's first major honour for 48 years, an exercise in embarrassment for Arsenal and, above all, a glorious triumph for Alex McLeish. A serial accumulator of silverware, the Scot declared his 20th trophy, the Carling Cup, his most meaningful in management.
It might yet prove still more significant, too: in the last nine years, other than at Manchester United, Arsenal, Liverpool, Chelsea and Tottenham, only two other managers have claimed a major prize. One, Steve McClaren, was rewarded with the England job; the other, Harry Redknapp, was headhunted at White Hart Lane. Unlike either, McLeish beat one of the elite in the final and prospered with more meagre resources, considering the context that others' spending provided. In short, it looks an auspicious achievement.
As the most successful of Sir Alex Ferguson's many pupils, it is unsurprising that there are suggestions that apprentice could follow master at Old Trafford. There were rumours, too, that Liverpool considered McLeish last season as Rafa Benitez's reign neared its end and after Birmingham embarked on a club record run of 12 unbeaten top-flight games. That the subsequent ninth-place finish has been followed by the capture of the Carling Cup means McLeish already rivals Arthur Turner and Gil Merrick for the title of the club's greatest manager; for anyone under 50, he stands alone.
The circumstances enhance his case. His astute deployment of his players indicates a keen footballing brain. One substitute, Obafemi Martins, scored the goal that won the Carling Cup; another, Nikola Zigic, changed the second leg of the semi-final against West Ham. Both were recruited this season and both help refute the charge levelled by the vice-chairman, Peter Pannu, who said in January that "most" of McLeish's acquisitions had "not substantially improved the team".
That a third newcomer, Ben Foster, was man of the match at Wembley indicates how silly that accusation now appears. The signings of Roger Johnson and Scott Dann predate Carson Yeung's takeover, but are now widely acclaimed as masterstrokes. Factor in an overachieving spell in charge of his country and the experience of managing under intense pressure at Rangers, plus an upstanding, honest personality that has earned the respect of players and neutrals alike, and McLeish's case for advancement may seem compelling.
Yet it should be ignored. This is partly because of what might be deemed 'the Roy Hodgson precedent'. Like McLeish, Hodgson had earned plaudits for his management of a smaller club. Yet like Hodgson, McLeish took his time to make his mark (Fulham were almost relegated in 2008, while Birmingham actually did go down) and time is not a commodity that the Englishman enjoyed at Anfield. And like Hodgson, McLeish has a penchant for careful planning that serves him well at a lower level.
It is no coincidence that Birmingham have drawn 22 of their last 53 league games - indeed, their participation in the relegation struggle can be attributed to a lack of adventure to convert some into wins. They can appear to play for a point, packing the midfield, employing a specialist anchorman in Barry Ferguson, and mirroring their manager's innate defensiveness although, to their credit, Birmingham displayed more attacking intent against Arsenal than they usually do against inferior opposition. Yet there is an expectation of excitement among the title challengers, and downbeat rhetoric and cautious tactics served Hodgson poorly.
The criticisms that can fairly be levelled at McLeish are that he has struggled to integrate individual talents at St Andrew's and that his side are the division's lowest scorers. It hardly helps that James McFadden is injured, or that Charles N'Zogbia's wage demands meant Birmingham rapidly lost the will to sign the Wigan winger. But while David Bentley has begun promisingly, Alexander Hleb ranks as the most underwhelming of McLeish's additions.
Aside a functionality that has served them well, they nonetheless have a flair deficit. That is not a problem at St Andrew's; it would be elsewhere. The same applies to others of Birmingham's characteristics. They have a team spirit that is built on a work ethic and an absence of superstars. It is entirely admirable, but not exactly an option at, say, Old Trafford. Squad rotation would be required, too, whereas McLeish favours an unchanged side.
His achievements in the last three years have granted him a leeway but, like many a manager, McLeish's negativity becomes more apparent when his decisions are queried. That would happen at a newer club, especially with a higher profile. As it is, his deserved popularity with Blues' support means he is protected in the stands, if not in the boardroom. His post-match comments about his achievement at Wembley could be construed as a veiled warning to Carson Yeung, an owner who got lucky.
Just how lucky may become apparent if McLeish is tempted elsewhere, but he might not be the right appointment for any of the favourites. An underdog mentality suits McLeish and Birmingham, as it did, in his time in international football, Scotland as well. He is a manager ideally suited to his current club.