It is what is called getting your substitutions right. As Mikel Arteta luxuriated in his first league win against Manchester City as a manager, one to enhance seriously the title prospects of his Arsenal team, to fortify their belief, he could reflect on how his stars had aligned after a triple change on 76 minutes. For so long, it had looked as though it could be another refereeing story. Nobody knows how this showpiece would have panned out if Mateo Kovacic had been sent off in the 35th minute. But Arsenal would have liked to find out. The City midfielder was a lucky boy. Already booked for a terrible tackle on Martin Ødegaard, Kovacic was playing with fire when he stretched in on Declan Rice to commit a clear foul. Rather than wave a second yellow card, which felt inevitable, the referee, Martin Oliver, allowed Kovacic to stay on. Arsenal rode out the storm. Arteta had sent on the fit-again Gabriel Martinelli at the start of the second half for his first action in three weeks and his mass move was to introduce Thomas Partey (also back to fitness), Takehiro Tomiyasu and Kai Havertz. The trio would link up to create the big chance for Martinelli towards the end and how he took it. Partey played a high diagonal, Tomiyasu headed back, Havertz made the lay-off. And when Martinelli shot, it deflected wickedly off Nathan Aké to sink City. Arsenal had lost their previous 12 games against the champions in this competition. They sorely needed to make a statement. The victory was built on emotional control and concentration out of possession. Arsenal restricted City, especially Erling Haaland, and Martinelli blew a cagey game open to spark delirium; a bit of post-match tunnel aggro, too. The visiting captain, Kyle Walker, appeared to clash with the Arsenal set-piece coach, Nicolas Jover, and some of his City teammates were involved, together with the stewards. Guardiola was asked if he was happy at how Arsenal had behaved. “Yeah, absolutely,” he replied, trademark sarcasm to the fore. City missed Rodri, who was serving the third game of his three-match ban for his red card against Nottingham Forest. They have now lost all three. Guardiola started with Bernardo Silva in front of the back four in a kind of Andrea Pirlo role, except with more running, Rico Lewis and Kovacic the No 8s either side. Silva helped to set a brisk early tone for City, emerging with credit. Arsenal needed time to work things out, especially without the injured Bukayo Saka, who they could not patch up and send out yet again. It was the first time in 88 league games that they did not have him. Arteta said Saka would not join up with England for the upcoming internationals. City almost landed the early blow, Josko Gvardiol hooking a corner goalwards from the far post and watching Rice head clear off the line. On the second phase, Haaland flicked on for Aké, who took a touch and lifted high from close range. Liam Brady was the pre-match guest and he was asked how excited he was. “I’m nervous,” the Arsenal legend replied. So were the home crowd, especially when David Raya looked to play out from the back and into City’s high press. The goalkeeper had to show his personality to stick to Arteta’s orders because he made mistakes early on and heard the Arsenal support urge him to play longer and more quickly throughout. Raya had shanked one pass when he dallied close to his line in the 17th minute and was tackled by Julián Álvarez, the ball squirting just wide of the near post. A let-off. City enjoyed theirs with Kovacic and it was an extraordinary one. His booking for clattering into Ødegaard’s ankle was in dark orange territory; the City player was given the benefit of the doubt after a VAR check. But his foul on Rice was a stonewall second yellow. “You don’t know what you’re doing,” the home fans informed Oliver. The tensions simmered, taking in the moment during the interval when Samir Nasri, working here as a media pundit, was aggressively accosted by an Arsenal fan in one of the concourses. What happened? “Just a guy who spoke shit because I left Arsenal,” Nasri replied. The man was ejected from the ground. With Jorginho in midfield, Rice had the licence to push up when Arsenal had possession and he impressed. The individual duels pounded, particularly William Saliba v Haaland. The second half came to feel locked, chances almost non-existent and Guardiola made his move with a triple substitution on 68 minutes that shone a light on Kalvin Phillips’s loneliness on the bench. On came the fit-again John Stones and Matheus Nunes in midfield, plus Jérémy Doku on the wing. It was Arteta’s response that changed everything.