Duff And Dunne Shine At Croke Park!
The 22-year-old Wolves striker came off the bench to level in injury time as Ireland fought back to deny Serbia victory.
Trapattoni's side looked to be heading for defeat when substitute Marko Pantelic, who had only been on the pitch for five minutes, made the most of Paul McShane's error to fire past Dean Kiely 15 minutes from time.
But Keogh volleyed home from close range in injury time to send the home crowd into raptures on a big night for their Iralian manager.
Across the city, another Boss was wowing an Irish crowd as Bruce Springsteen played to an adoring audience, perhaps a better bet than the Eurovision Song Contest going on at the same time in the Serbian capital Belgrade.
But at Croke Park, all eyes were on Trapattoni, who was greeted by rapturous applause as he made his way to the bench having swapped the tracksuit he has worn all week for a suit.
Ireland will head for Craven Cottage and a meeting with Colombia on Thursday night before they launch their World Cup qualifying campaign in Georgia in September.
Newcastle midfielder Damien Duff has endured a miserable two seasons in England, with injuries and a lack of form leading to speculation that his international days might be numbered.
However, having impressed with his industry and enthusiasm under the Iberian sun, he carried on in the same vein on a chilly night in Dublin to inject a little pace and invention into a tight opening 45 minutes.
Most of what was good came through Duff down the Irish right, and it was he who created his side's best chance with 22 minutes gone when he tricked his way past impresive full-back Ivica Dragutinovic to send in a dangerous cross.
At the other end of the park, defender (and Kevin Keegan target) Richard Dunne was equally impressive despite only meeting up with his team-mates on Thursday evening.
He made a series of timely interventions as Serbia wide-men Stefan Babovic and Bosko Jankovic, prompted by playmaker Sasa Ilic, provided support for striker Danko Lazovic.
Rep of Ireland: Kiely, Kelly, Dunne, McShane, Delaney, Duff,Miller, Whelan, Hunt (Keogh 81), Keane (Daryl Murphy 70),Doyle (Long 86).