When the red card was raised to David Luiz and Jorginho converted the resulting penalty, it seemed the night was about to get ugly for Arsenal. The last time they were reduced to 10 men early in a game here, in March 2014, they lost by six goals. Another collapse felt inevitable.

But if ever there was a performance to suggest that Arsenal might finally be turning a corner, that they might finally be overcoming all the mental frailties and psychological scars of the past, then this was it. Instead of crumbling, they regrouped and showed a level of determination in the face of adversity which had seemed lost to them for too long.

Arteta proud of Arsenal spiritPremier League highlights

From the first whistle right up until his substitution in stoppage time, Martinelli gave absolutely everything he had. When he wasn’t attacking the Chelsea box, charging inside from Arsenal’s left flank, he was tracking back, chasing down lost causes and snapping into tackles and interceptions in front of his full-back – and fellow teenager – Bukayo Saka.

“To play in this stadium, in the way he has done, with 10 men, and against [Cesar] Azpilicueta, who in my opinion is one of the best defenders in the Premier League, you need courage,” said Arteta afterwards.

“I wanted to take him off a few times because he looked knackered and he was cramping, but the next minute he is sprinting 60 yards again.”

FREE TO WATCH: Highlights from Chelsea’s draw with Arsenal

FREE TO WATCH: Highlights from Chelsea’s draw with Arsenal

That speed and stamina was certainly evident for his goal, when he ran the length of the pitch and still had the composure to slot home a cool finish. It can also be seen in the tracking data which shows he made nearly twice as many high-intensity sprints as anyone else at Stamford Bridge.

His work-rate was remarkable, but it was not the first time it has stood out. In fact, he has registered the most sprints in every one of his five Premier League starts so far. Freddie Ljungberg likened him to a “Duracell battery” during his interim tenure and Arteta has been similarly impressed.

Even in the closing stages against Chelsea there was no let-up. At one point, around 10 minutes from time, he could be seen hurtling towards Azpilicueta to put him under pressure just inside the Arsenal half, only to then pop up near his own byline seconds later and close down Callum Hudson-Odoi as he attempted to break into the box.

His energy and enthusiasm set the tone for Arsenal’s performance, but it’s his clinical edge in front of goal that marks him out as a potential superstar. His 10 goals so far have come in just 1,125 minutes of senior action – and mostly from wide positions. He is already the first teenager to reach double figures in a single season for Arsenal since Nicolas Anelka.

Bellerin scored after Cesar Azpilicueta had put Chelsea back in front Bellerin scored after Cesar Azpilicueta had put Chelsea back in front Bellerin scored after Cesar Azpilicueta had put Chelsea back in front

His record places him in esteemed company across Europe too.

In fact, so far this season, the only teenager in the continent’s major leagues to have scored more goals is Borussia Dortmund’s Jadon Sancho. Arteta still has plenty to work on at Arsenal, but that statistic alone provides hope for the future and the role that Martinelli could play in it.

Arteta could find further encouragement in some of the other performances against Chelsea, of course. There was praise for Alexandre Lacazette and Nicolas Pepe for their selflessness, while Granit Xhaka was singled out for his leadership in a makeshift centre-back role. “Every single player stood up,” added Arteta in his post-match press conference.

But none more so than Martinelli.