There may be a sense of existential drift around the squash-ladder format of Uefa’s new Champions League, a sense of slackness, of football happening just because money says it has to happen. But you can only beat the 35 teams in front of you and this was on its own terms a very good win for Arsenal. It was also something new, a 2-0 defeat of Paris Saint-Germain in front of a boisterous crowd but also a win against the champions of France that is still essentially a marker and a warmup for other stuff. The only way to exit this thing outright in the first phase is to finish 24th or below in a 36-team table that also contains Young Boys and Slovan Bratislava. The richer clubs wanted this, a chance to play each other constantly, to have a good time all the time. Product duly happened here. But for Arsenal it was still instructive in its own way. They kept a clean sheet. Mikel Merino made his debut as a substitute. Bukayo Saka was excellent in a tight game against a good defensive team. And the two first-half goals both came from notable moves. The first arrived via a bullocking direct-football centre forward’s header from Kai Havertz. It was beautifully made, Leandro Trossard ferrying the ball down the left hand channel, waiting for the pieces to align, then dipping the perfect diagonal cross into the path of Havertz’s stealth-run in behind the defensive line. Havertz may gambol about the pitch like a medical student on a fun run. He may have the wan good looks of the kind of minor Jane Austen character who rides off on a horse after an unsuccessful marriage proposal. But he is also very good in the air. And this was a wonderful piece of skill and physicality, the leap taking him above and also through Gianluigi Donnarumma, and in the same movement nodding the ball into the empty net behind. It was Havertz’s third goal in the last week, all of them poacher-ish affairs. He is a leader in this team now. The second on 35 minutes was very funny in its own way. On the morning of the game L’Équipe had carried a deconstruction of Arsenal’s set-piece threat, concluding with a slightly dismissive wave of the hand, that this kind of thing is, thankfully, “made for the Premier League” where “the refereeing body is rather permissive”. OK. Let’s see how that all panned out. The goal came from Saka’s free-kick wide on the right touchline. Arsenal’s attacking five were bunched together at the back post. Moments before the ball was floated in they set off on a straight line jog, knees theatrically high, like sailors in a musical production off to hoist the rigging. The PSG defence seemed hypnotised by this, horrified that such subterfuge could exist. Saka swept the free-kick in, Trossard swung a foot, and the ball floated in though the crowd without a touch. Dark arts. Voodoo-ball. Blokes running in a line. Whatever will they dream up next? But there was planning here, too. PSG had been told to mark zonally. And frankly they were just really, really, going to obey those instructions come what may, even when it makes no sense because all the people who want to score are running the other way. Best of all, Arsenal produced a welcome piece of game management here. Getting to 2-0 up with 35 minutes gone was significant, as was the ability to keep it like that. There is perhaps a slight issue in the way they win. Intensity is the default setting. This team runs on thigh revs all the time, has no down gear, doesn’t cruise. As a result Arsenal tear into almost every game like it’s a hot dog for a starving man. And before tonight they hadn’t won more than a couple of games in an obviously straightforward way since April. There is so often drama, a sapping of the emotional energies. Games remain alive to the final 10 minutes. Luis Enrique was present here in shiny lace-ups and black suit, the look of a sightly haunted executive undertaker. It made a pleasant change to see the opposition manager flailing around on the touchline as time ticked down and Arsenal protected a lead that always felt secure. This is of course PSG in its post-star phase. The word from France is that this is more of a team now. Yes: the most expensively assembled group of players in mainland Europe is now condescending to actually be a team. And not just any team, but the team-est of teams. We will now devote all our plasticised project energy to being real. This is undeniably a different entity, young and energetic with more of a homegrown feel. The test for Paris, as ever, is – can you jog through the league then sprint when you need to in midweek? On this evidence they have basically found another way to noodle about. They showed great technical skill in keeping the ball. They made chances. They also looked just a little toothless. Whereas for Arsenal this was cold, clinical and just the kind of win they probably needed.