The towering striker known as "Big Ziggy" to his team mates scored the opening goal at Wembley and helped set up Obafemi Martins' late winner in Birmingham's surprise 2-1 victory.
With four goals in his last five appearances, Zigic is finding his form at the right time for the Midlands club who hover just two places and two points above the Premier League drop zone.
Although his grasp of the language is not quite there as he politely declined interviews in English following Sunday's victory, the former Valencia and Racing Santander player was all smiles as he spoke in Spanish picked up from his La Liga days.
"I'm loving training and now that I'm getting to know the guys better things are great," the smartly dressed Serbian international, who joined Birmingham from Valencia in May last year, told Reuters while battling to cling onto Cup memorabilia tucked under his arms.
Standing 6ft 8 ins tall, target man Zigic's aerial ability can trouble any defence, as Arsenal found out when he swivelled to head in Birmingham's opener after 28 minutes.
He is popular with Birmingham fans who recognise the importance of his aerial prowess to the team.
Fellow striker Martins exited the media area shortly after Zigic with a blue hard hat given to him by the Birmingham supporters. On the front was a cross with the words "Zigic, head here" written underneath.
Zigic was at Valencia when they clinched the 2008 Spanish King's Cup, so he knows what it is like to win silverware, but with Birmingham deep in a relegation battle the significance of Sunday's win was not lost on the Serb.
"It's not easy to win titles in England so this is a big forward step for us, and hopefully next season we'll still be in the Premier League.
"This win helps a great deal. We'll enjoy the moment but from Tuesday we have to prepare for West Bromwich Albion," the 30-year-old said of the derby with their fellow strugglers on Saturday.
Zigic is also hoping for better times ahead with his national side.
After their 2012 European Championships qualifier against Group C leaders Italy in October was abandoned due to crowd trouble and the opposition awarded a 3-0 win, Serbia have a tough task to reach the tournament finals.
More worrying is UEFA's threat to throw Serbia out of the qualifiers if there is any repeat of the crowd violence against Italy.
"It's a tough group. We have quality but we need more luck. The Italy loss hurt us badly but I think we can overcome that," said Zigic.
"We know two teams will qualify so I think that will help us."
As for his club career, Zigic is growing in popularity at his new home but like his own frame he still holds ambitions of playing for one of the giants of the sport.
"One day I'd love to play in a big team but for now I'm happy in Birmingham."
