During the quarter- and semi-finals of the Quidditch World Cup in 1809, Popa and his teammates saw Nenad, who was noted for his violent and unstable behaviour, hit himself over his head with his broom and set his feet on fire out of frustration. On two occasions, Nenad was driven to strangle a referee, and both times Popa intervened to stop him. Popa and the other players voiced their concerns about Nenad to the team's manager, urging him to substitute another player for the final, but to no avail.
Two hours into the final match, when Romania was losing to New Spain, Nenad deliberately sent a Bludger flying into the nearby forest, thereby causing the trees he had jinxed before the match to come to life and attack the stadium. Several people were killed in the ensuing chaos, including Nenad, but Popa managed to save lives through his actions.
Popa was later received an International Wizarding Order of Merit for the heroism he displayed during the catastrophe. At an international inquiry that was convened, he testified that he had no idea what Nenad was planning to do, stating, "I mean, who'd suspect that? You'd have to be as mental as he was."