Among the spectators at the Emirates Stadium on Tuesday night was Mykhailo Mudryk, the Chelsea winger. Watching from the stands, Mudryk must have experienced an unusual set of emotions: this was a match between the team he used to play for, and the team he almost joined. Oh, what could have been.

It is easy to forget now, almost two years later, how much Arsenal wanted to make Mudryk one of their own. They were willing and ready to make him one of the most expensive players in their history, until Chelsea produced perhaps the most dramatic transfer hijack of recent years to snatch him from Shakhtar Donetsk.

How strange it is to think that Arsenal, back in the winter of 2023, effectively saw Mudryk as an upgrade on Gabriel Martinelli. They certainly were not going to pay more than £50 million for the Ukrainian to be a mere backup option, and Martinelli operates in the same left-wing role. If Mudryk had moved to Arsenal, Martinelli’s position would have been under serious threat.

These days, to suggest Mudryk might be an upgrade on Martinelli would be to reduce a room full of Arsenal fans to disbelieving laughter. There is no doubt now which player Arsenal would rather have, and he was the one on the pitch here, not the one sitting high above the action.

On a stodgy night for Arsenal, it was Martinelli who provided the electricity that Mikel Arteta’s side required against complicated opposition. Shakhtar posed some awkward questions, especially in the second half, but Arsenal had the most effective attacking player on the pitch. No player ran harder — or indeed faster — than the Brazilian on Arsenal’s left flank.

“He looked really sharp, really fresh,” said Arteta. “Fresher than anybody on the pitch. He had another gear, he had another level of threat.”

The winning goal will not be credited to Martinelli but it was undoubtedly of his making. Cutting inside from the left wing, providing a trademark burst of speed, his low shot bounced off the near post and into Shakhtar goalkeeper Dmytro Riznyk before trickling over the line. “It was my goal,” Martinelli later claimed, although the authorities will not agree.

As Arsenal struggled in the second half, Martinelli almost single-handedly kept the home crowd engaged. There were more purposeful runs, a powerful shot on target and plenty of energetic defensive work. With 10 minutes remaining, he seized possession on the edge of his own box and surged downfield as his team-mates ambled around behind him.

Encouragingly for Arsenal, Martinelli’s performance was in keeping with his recent upturn in form. The 23-year-old is not quite back to his best, but he is getting there – and there is no doubt that Arsenal need him to deliver, especially in the ongoing absence of Martin Odegaard and Bukayo Saka.

Martinelli came into this meeting with Shakhtar on a run of two goals in his previous four matches, including a crucial effort against Southampton. They were much-needed goals for a player who had been sapped of confidence over the previous months. Before his goal against Leicester City in late September, Martinelli had not scored for his club since March.

Nights like these provide a reminder of why Martinelli was, not so long ago, regarded by Arsenal as an equal to Odegaard and Saka in terms of importance. Last season’s struggles damaged his standing, and led some to wonder whether Arsenal’s executives were right to consider an alternative left-winger after all. This was a riposte to those suggestions, with Martinelli proving he remains a player who can make all the difference.