The Slavonian Mts. (including Mt. Papuk), located in the southwestern part of the Pannonian Basin in Croatia, consist mostly of a pre-Alpine crystalline basement made of igneous and metamorphic rocks (Tisia Mega-Unit). However, at the Trešnjevica geosite from Mt. Papuk (Papuk UNESCO Global Geopark), dike swarms of igneous rocks cut through migmatitic gneiss and granitoid from the Variscan basement. These younger rocks are classified as basalt, andesite and rhyolite. Their mineral assemblage and chemical composition reflect the high-temperature, dry and oxidised nature of magmas typical of a divergent tectonic setting (A-type for the acidic varieties). Accessory zircon from four rhyolite and one andesite sample was used to unveil the timing of the magmatic event and constrain the origin of the parental magma. Zircon dating (LA-ICP-MS) reveals a Late Cretaceous (between 81.1±1.1 and 81.5±1.1 Ma) and brief (< 3 Ma) magmatic pulse. The geochemical record of zircon (trace elements and Hf isotopes) indicates a magmatic origin as an early crystallised phase in a deep magma chamber at relatively high (~850 °C) and constant temperature. The parental magma was derived either directly from melting of a metasomatized mantle or from re-melting of mafic lower crust extracted from mantle earlier. The new zircon data support previously proposed geodynamic models, which suggest the formation of deep rifts and melting in a late-orogenic setting during the Late Cretaceous closure of the Neotethys Ocean. The ultimately mantle-derived melt underwent extensive fractional crystallisation and evolved towards a rhyolitic composition during its ascent through the slightly thickened crust (up to 42 km).