The Rats entertained fans at the Hawth Theatre in Crawley as they prepared for two nights at the London Palladium.
Geldof and the band played their big hits like I Don't Like Mondays, Rat Trap - in which the saxophone player also wore a Crawley Town shirt - and She's So Modern along with new material.
And for the encore, Geldof returned to the stage with a Reds shirt on which had his name and the number 70 - his age - on the back. The shirt was presented to the Rats' tour manager and Crawley Town fan Mark Welch before the gig by manager John Yems.