FNC 15 took place on March 30, 2024, at the Arena Stožice in Ljubljana, Slovenia. This event marked the promotion's highly anticipated debut in Slovenia and was one of the biggest MMA spectacles in the region's history. In the main event, local hero Miran "Slo Rocky" Fabjan continued his incredible run by knocking out the dangerous Croatian finisher Mario Žgela in just 45 seconds of the first round. The victory sent the home crowd into a frenzy and set up a massive future showdown with Darko Stošić.

FNC 15: Miran Fabjan vs. Mario Žgela