We’re back, baby. So, back. Well, okay, not exactly back. But going back in the time warp, at least for a while, as on a pale blue afternoon at the Emirates Stadium, Arsenal and Chelsea produced an opening half-hour that felt like a throwback to the excellent Barclays of the early 2000s. In that period, this really did feel like a twist on a classic: killer ball attacks in midfield, full-backs stretched and nervous, players darting at defensive lines like the scapegoats in a western of cowboys being dumped through the lounge bar doors. Arsenal took 10 shots in that period and played breathless, physically overwhelming attacking football. The match was resolved after scoring the tie. In the second half it became simply exciting and episodic, interrupted by substitutions and saves, which is the current dynamic. Second halves: these are a problem. But Arsenal never really looked like losing their 2-1 lead. The key to the day was that pleasingly wild opening half hour, evidence that both teams have the will and energy to progress this season. Which, in turn, will be good news for the Premier League. About last season. It was good, wasn’t it? Lots of football in demo mode. Games that were like watching someone knit a scarf. On teams with elite levels of defensive organization, the experience is like watching one of those police teams on motorcycles displaying a pyramid, while a group of men on laptops furiously study the data. Everything very orderly and disciplined. It only lacks color and fire. More importantly, the higher gears mean you could actually run step by step with the Paris Saint-Germain, or fly, rather than slowly strangle, an opponent. It’s about balance, of course, about releasing the impulse for total control. There was a moment in the 87th minute that captured both sides of this. Chelsea were awarded a free kick 25 yards from goal: high drama, a moment to seize, necks craning forward in the seats. At that moment, late substitute Danny Welbeck ran straight towards Reece James as he prepared to shoot, looking like a man on high alert, executing some vital mission. Welbeck’s mission turned out to be to hand James a piece of paper and urge him to read it. What was this? Expected numbers of free throws in the 87th minute? Forty-seven percent scoring chances rise up and to the left? Maybe it just said “Score, dufus,” in which case, more of this, please. James studied him diligently and then ran again. And to be fair, if the note said, “Kill it right on Declan Rice’s head, then job done, great process everyone.” But the predominant feeling was: no, thank you. Away with you, you interventionist idiots, control freaks in tracksuits! This is art. This is play, this is drama. Whatever it is, this is definitely not the time for a briefing. Kai Havertz equalizes for Arsenal in a dizzying half hour. Photograph: Paul Childs/Action Images/Reuters The other thing, simultaneously to this, was Morgan Rogers walking around the pitch and being relentlessly harassed by Arsenal fans – “You should have signed for a big club” – but looking exhausted, exhausted and emotionally drained, after giving his all in that part of the show that seemed the counterpoint to Welbeck’s note, the wildness and energy that fuels this. There was really nothing I didn’t like about that beginning, which was all improvisation. all sugar rush. First there was the confrontation between coaches, a kind of Basque children’s romantic comedy revenge drama. The league needs sibling rivalries and symmetry. It feeds on these things. Hmm. Maybe they need to start beating their chest a little more. But it was still fascinating to see Xabi Alonso in the band. This was fresh meat to behold: jawline, pecs, tan, elite smart-casual style, and above all, a sense of natural aura. There’s a new sheriff in town. The sun had even appeared, giving off a strange, dead September heat, and the sky behind the stands was a pale Hockney blue. And Chelsea scored with 1 minute and 17 seconds, Rogers finishing the volley with a measured and very deliberate shot into the corner. For a while, these two teams simply butted heads. Emi Martínez received a kick in the head but got up and was still being booed relentlessly. Arsenal had a goal disallowed. They produced a fluid and complete movement, created by a lovely twist and turn from Myles Lewis-Skelly. In the 25th minute, the score was 1-1. The goal was the work of Kai Havertz himself, who came in like a lanky, studious Arjen Robben and then fired low near the post. Every weekday Subscribe to Football Daily. Start your evenings with the Guardian’s take on the world of football following the newsletter’s promotion. Havertz was also involved in the decisive moment, producing a charming and indeed deeply unfashionable dummy to place Martin Ødegaard in the space in front of goal. It wasn’t even really a dummy, Havertz simply dribbled with his foot, without any real feint or shoulder movement in the classic dummy style. Arsenal fans are sometimes frustrated with Ødegaard. He’s not direct enough, he doesn’t shoot, he always gilts the lily, gilts it again, takes it to the gilders to have another look. Maybe that’s how you get him to shoot. Put him right in front of the goal with time to look at all the options, do the numbers and conclude, ‘oh well, am I really going to have to do this?’ The ending was emphatic. After that, the game got grumpy and mean for a moment. Arsenal entered one of their slow periods, taking the wind out of them and killing the game a bit. But this was an excellent victory against a very promising Chelsea team. One last thought. The question will be asked: why don’t Arsenal always play like this? Why stop with rage and gallops forward? The answer is that you can’t. It is physically very hard. This is not a computer game. They are human, with 90 minutes left. The real question is: can you bring it up again, take that 30-minute spell and put it away, keep it ready in your repertoire? If so, and based on the evidence here, we could really have an Arsenal upgrade on our hands.