Minutes after coming on as a substitute, it didn't take long for RB Leipzig's defenders to become introduced to João Félix and his mazy dribbling ability.
Picking up the ball near the halfway line, he quickly drove forward at their defence, forcing Konrad Laimer to step out of position and teeing up Renan Lodi for a dashing run into the box. Dayot Upamecano was then forced to take out the Brazilian left-back, causing those from Atlético Madrid to furiously gesture for a penalty, while their opponents nervously awaited referee Szymon Marciniak's decision to turn away their protests.
If that wasn't enough to accelerate Julian Nagelsmann's heart rate, then the next jinking run from the 20-year-old certainly did.
With his first touch getting himself past Marcel Sabitzer's challenge, the Portuguese youngster surged forward, with his pace too quick for any defender to stop. Playing a one-two with Diego Costa, he continued to dribble into the box, and just as he was steadying himself to shoot, Lukas Klostermann desperately slid in and tripped him.
There was no argument from the German defender, as he knew fully that his team was set to lose their one-goal lead if he hadn't made the challenge. Dusting himself off, Félix placed the ball on the spot, took a breath and coolly slotted the ball past Péter Gulácsi to level the tie at 1-1.
Suddenly, the game was up for grabs for Los Rojiblancos. His converted penalty marked a shift in the game's momentum, with the German side now looking the more vulnerable of the two teams, while their counterparts looked re-energised.
Ultimately, it wasn't to be for Atléti, as Tyler Adams' deflected winner gave the Bundesliga outfit the victory needed to make the final four. The tournament was over for Los Indios, who now fly back to the Spanish capital, their 2019/20 campaign officially over.
Still, Félix's second-half display will be of huge encouragement for the Spanish club, ending a difficult first year in Madrid on a high. Signed last summer to be the long-term replacement for the outgoing Antoine Griezmann, he's been hampered by multiple injuries which have prevented him from gaining a regular run in the first team.
Also stunting the 20-year-old's progression this season has been Diego Simeone's inability to figure out how best to deploy him in his preferred 4-4-2 formation. He was initially selected as a right winger, only to be moved centrally mid-season in a bid to get him on the ball more often.
Having arrived from a free-scoring SL Benfica side who scored 140 goals in 2018/19, it has taken him some time to adapt to the Argentinian's style of play, which requires players to exert a greater level of defensive pressure and intensity on the pitch.
His fitness has been lacking at times – due in part to his youth, and his niggling injuries – which has resulted in him getting substituted early on whenever he's started, and explains why he's appeared to be more successful as an impact substitute for Atléti.
Still, the Portuguese forward has shown flashes of brilliance when he's been fully fit. Most notably, he was fantastic in their 3-2 Champions League win against Liverpool at Anfield, and even off the bench he's produced some memorable displays against the likes of Sevilla and Villarreal in La Liga.
It's undeniable that Félix possesses the skills to be a world-class attacker for a long period of time. When he's at full pace dribbling past opponents at ease, cutting inside and bursting into the box to create goalscoring chances for himself or his teammates, there's few who can stop him.
Having contributed with nine goals and three assists in all competitions, the 20-year-old has not had a terrible season by all means. It's just unfortunate that his performances have been judged against the £113m (€126m) he cost the Spanish side, which remains the fourth-highest transfer fee of all-time.
There's no doubt that he'll continue to improve next season. A fully fit season, with an improved fitness base, would do wonders for the 20-year-old, who will perform better in Simeone's system. Despite some questioning if the Argentinian boss is the best man for him to thrive under, the player himself has made it clear he wants to learn and improve under the man nicknamed 'El Cholo'.
"I'm here to play Cholo football."- João Félix, speaking to Marca
After all, the forward only has to look at Griezmann's development at Los Indios as a guide to follow. With the Frenchman netting 133 goals in his five seasons in Madrid, there's no reason to think that his younger replacement can't go on to ape such goalscoring exploits, even if it takes him some time to get there.
So while Los Rojiblancos depart from Lisbon with great disappointment at their quarter-final exit, there should still be plenty of optimism and excitement around Félix, who showed himself to be a talented star in the making. Give him the time, and he will develop into one sooner rather than later.