The 19-year-old already has a goal and an assist to his name in La Liga, playing a pivotal part in guiding Diego Simeone's side to the league summit prior to the international break.
After seeing Atletico go 2-0 down early against Eibar last weekend, Felix sparked his new team into action, scoring their first goal in the 27th minute as he tapped home from close range having initially unleashed Diego Costa.
A late winner from Thomas Partey would then seal Simeone's men all three points and ensure they are the only club in Spain's top-flight to win all three of their opening league games.
"I knew he had great talent, great potential," goalkeeper Jan Oblak said of Felix after the game.
"The club has made a lot of effort to bring him here and we all agree that they have brought a high-quality player and that he can become one of the best, for sure.
"At the moment he is playing very well and hopefully he continues like this, giving us joy."
With Barcelona and Real Madrid both stumbling early on this season, Atletico have been given a real head start and with Felix up their sleeve, they should be considered genuine title contenders - even if Simeone isn't getting ahead of himself.
"Everybody is very excited but we have to stay quiet and work," Simeone said after seeing his side come from behind to defeat Eibar.
While the defending champions did claim more silverware in June by winning the inaugural Nations League final against Netherlands, Fernando Santos' side have made a slow start in qualifying for Euro 2020.
Though Cristiano Ronaldo isn't showing any signs of slowing down, Santos needs to find another attacking X-factor and Felix looms as an ideal candidate.
Making his senior debut against Switzerland in June, the 19-year-old, much like in his La Liga debut, didn't really impress as Portugal emerged 3-1 winners.
"He could never really got a foothold in the game," Alan Smith told Sky Sports. "Most of it went on around him but he will learn from that."
Full of confidence after his bright start to life in Madrid however, the time is right for Felix to be given another chance to shine for his nation with matches against Serbia and Luxembourg to come over the international break.
Serbia, who Portugal play on September 7 in Belgrade, conceded five goals against Ukraine when they faced off in June, making their shaky defence an ideal early test for Felix.
In his international debut against the Swiss, the teenager played off Ronaldo up front in a partnership that could bear both some tantalising short and long-term fruit.
Like Batman and Robin, the duo could form an iconic pairing over the coming years with Felix in the process left in an ideal position to take over the Juventus star's mantle.
Ronaldo, now 34, was crowned Portuguese footballer of the year for a 10th time last week and his understudy has made no secret of his admiration.
"Cristiano Ronaldo has won five Ballon d'Or trophies and this is the dream of every player," Felix told ESPN in July. "Obviously I would like to be like Cristiano."
Despite playing just one game together to date, Ronaldo seems in little doubt that Felix could be capable of filling his shoes one day.
"Can he repeat my successes in Spain? I believe that a lot, because he is an excellent player with a lot of potential who can evolve," Ronaldo said in an interview with TVI.
While Felix has started life on the right foot in La Liga, the teenage superstar will be desperate to now do the same for his nation as Portugal look to get their Euro qualification campaign back on track.