At PRIDE 23, Arona would go against Murilo Rua, a member of the Chute Boxe team, which was in a rivalry with Brazilian Top Team at the time. The two contenders fought a series of battles on the clinch, in which Arona imposed his superior wrestling, and almost finished the fight with a rear-naked choke and an Achilles lock at the end of the first round. The match went back and forth, with Murilo escaping from sparse submissions and landing his famed strikes, but Arona overpowered him with takedowns and kicks at the end and won the unanimous decision.