Wembley - Obafemi Martins' 89th-minute winner following a blunder from goalkeeper Wojciech Szczesny and Laurent Koscielny gave Birmingham a 2-1 victory over Arsenal in the League Cup final on Sunday for its first trophy since 1963.
Szczesny and Koscielny went for the same ball from Nikola Zigic's long pass and the ball landed at the feet of Martins, who slid it into the net.
"I think it was my second touch," said Martins, who joined Birmingham on a six-month loan from Rubin Kazan last month. "I think this is the easiest goal I've ever scored in my career - and it's very important."
Zigic had exploited defensive frailties to head Birmingham in front in the 28th minute, but Robin van Persie volleyed Arsenal level 11 minutes later.
Birmingham first major title since the 1963 League Cup final prolongs Arsenal's search for a first trophy since the 2005 FA Cup.
While Birmingham is battling against relegation from the Premier League - sitting two points above the drop zone - Arsenal is second behind Manchester United.
"It's an achievement when you consider who we were up against," Birmingham manager Alex McLeish said. "We weren't given a prayer by the pundits and the bookies but we believed today. It was a titanic performance by the players.
"We had a game plan and managed to get our noses in front, that gives you a great chance."
Three finals have been lost by Arsenal since 2005 as manager Arsene Wenger's wait continues for his youthful side to have something to show for its eye-catching football.
That lack of success, Wenger conceded before the match, had placed "a weight on the team." Only this season has Wenger selected strong sides in the League Cup, which he had derided in previous years and fielded young players.
Wenger hoped the final would show how far his side has matured, but Arsenal was sluggish and struggled to impose itself.
The Gunners looked nervy as passes went astray and had failed to heed the warning of Fabregas before the match that you are likely to lose when contesting the ball in the air with Zigic.
That transpired from a corner after Arsenal right back Bacary Sagna had conceded possession. Birmingham defender Roger Johnson soared above Koscielny to meet former Arsenal winger Sebastian Larsson's corner and nodded goalward to Zigic.
The Serbia striker - the Premier League's tallest player at 2.03m - found space among five Arsenal players to head beyond Szczesny.
Szczesny had been fortunate to still be on the pitch at that point. Inside the opening two minutes, the Polish goalkeeper brought down Lee Bowyer, who was adjudged to be in an offside position despite Gael Clichy appearing to play him on side.
The equaliser came after Jack Wilshere hit the crossbar from the edge of the edge of the penalty area and the rebound was only partially cleared by Barry Ferguson's header. The ball fell to Andrey Arshavin on the right flank and his cross was volleyed home by Van Persie.