The very next day, AIK announced that young Filling had signed a his first professional contract to keep him at the club until June 2028.
"It feels completely unreal to sign my first contract with AIK," he effused. "It is a dream come true to be able to step up to the men's team at the age of 16 and now I look forward to continuing my development in order to achieve my next dream in the future, which is to win the Swedish Championship gold medal with AIK."
However, Filling's goal-scoring exploits on his debut unfortunately did not spark an immediate breakthrough, as it emerged that the teenager had suffered a knee injury. That problem would keep him out for two months, and he has since been eased back into action - starting just one out of eight matches since late August, albeit he will still be happy with that level of game time at his age.
He has, though, bagged his second senior goal for AIK in another euphoric moment, rising highest to head home a 96th-minute winner against Stockholm rivals IF Brommapojkarna. "This is the best there is, this is how football should be," he told HBO Maxafterwards with his arms spread wide in a refreshingly enthusiastic interview. "A chance, a goal, it's enough."
At international level, Filling already forms part of Sweden's U18s squad and recently netted a brace against Wales in a friendly. He had already represented the U15s, U16s and U17s, and seems destined to make his senior bow in the not-too-distant future.