It’s the hope that kills you. Also conceding 21 shots on goal including six big chances: to be fair, that kills you. Also leaving Lauren James one-on-one with your defender, who inconveniently isn’t actually a defender: that also has a tendency to kill you. Also, the needless red card for lipping the referee. Also, not taking your own chances. Also, going into the game seven points behind in the first place. Regrettably, all fatal.

Arsenal will grouse and Arsenal will grumble. Arsenal will sigh over small details and mutter deep-state conspiracies about refereeing standards. But Arsenal are also done. Chelsea’s first league double over them since 2019-20 also marks the factual end of what we technically, and generously, have to call their challenge for the 2024-25 Women’s Super League title.

Related: Sonia Bompastor salutes her Chelsea side for ‘huge’ win over Arsenal

Eleven points the gap two seasons ago. Five points last season. Now 10 points, with every chance of getting wider. Afterwards the new permanent head coach, Renée Slegers, mourned the “small details” that cost her team this game. But over the longer term it is increasingly the big details that are costing Arsenal, details that no refereeing controversy can remotely explain on its own.

With an immaculate sense of theatre, Chelsea unveiled their new signing Naomi Girma on the pitch just before kick-off. And yet if there was a certain hubris at play in parading their world-record defender under the noses of their jilted rivals, then as Girma stepped out of the tunnel into an absolute dose of British weather – torrential rain and howling gales – nobody could have blamed her for disappearing back down the tunnel and booking the first ticket back to San Diego.

Manchester United climbed up to second in the Women's Super League with an emphatic 3-0 victory at home to an out-of-form Brighton side.

United's fourth straight league win puts them seven points behind the leaders Chelsea as the high pressing and intense work rate of their front four caused Brighton problems, particularly in the first half.

The fit-again England midfielder Ella Toone opened the scoring inside two minutes with a low finish after bursting clear, adding to the hat-trick she scored a week earlier in the Manchester derby. The Japan midfielder Hinata Miyazawa drove in with power to make it 2-0 as a rebound rolled to her in the box after a free-kick. Celin Bizet added a third in the second half from long range. The home side thoroughly deserved their victory.

Defensively, Brighton were poor, and they have now lost three games in a row in all competitions, but remain fifth in the table. They remain winless away from home in the WSL since October.

Earlier, the Denmark midfielder Olivia Holdt had scored a 95th-minute free-kick on her Tottenham debut to give her new side a dramatic 3-2 victory away to the bottom side Crystal Palace. Bethany England also scored a brace for the visitors to become the first player to have scored against every different team that has featured in the WSL.

There were also valuable home victories for both Leicester and West Ham, boosting their hopes of avoiding relegation and adding a further downer to Crystal Palace's afternoon following their last-gasp defeat.

Leicester came from behind to beat Liverpool 2-1 thanks to a third goal in four games in all competitions from Missy Goodwin, ending the Foxes' six-game winless streak in the league.

West Ham were 2-0 winners at home to Everton as Shekiera Martinez and Viviane Asseyi both got on the scoresheet, ensuring the hosts have now won three of their past four home league fixtures.

Tom Garry

But of course Girma has endured much tougher ordeals in her 24 years: career-threatening injuries, discrimination, loss and heartache, facing some of the best strikers in the world, working with Jonas Eidevall for two weeks. And in a way this was a game that encapsulated why Girma has chosen London blue over London red, why Arsenal – arguably the club that needs her more – are not getting her.

It was a taut and well-matched game played in horrible conditions, the sort of game that you always feel is going to be defined by an error rather than a moment of brilliance. Early on a lot of those errors were coming from Leah Williamson: a bad early touch, a lost physical duel, a pinged long ball straight out of play, and whenever she got the ball Mayra Ramírez aggressively charged down the space between them, scenting a rich feast.

But Williamson recovered her composure, Arsenal got a foothold in the game and eventually some possession in promising areas. These are the periods in which Chelsea need to be finished off, the periods that require tempo and purpose and belief and controlled aggression and above all a sadistic clinical edge, the desire to find your opponent’s weakest point and keep squeezing it.

Instead, you could pick out all kinds of passages where Arsenal did the opposite. Alessia Russo getting a gift from Erin Cuthbert in the first half, and her instinct not to drive through the centre but to check wide, the path of least resistance, the path that Millie Bright is happiest for her to take. Beth Mead taking a touch instead of shooting first time. Endless examples of Arsenal players passing the ball with no chill, without committing an opponent, with no real wider strategy beyond the pass itself.

There is a common thread here, and you see it off the pitch as well as on. By any measure, Arsenal should be the dominant power of women’s football in England. They generate the most revenue, the most buzz, consistently draw crowds that put other clubs to shame. Where is the assertiveness and the arrogance? Where is the single-minded determination to be sole author of their own destiny? Where is the January transfer blitz that might have helped bridge the gap, bulk out an overworked squad?

Why impose entirely theoretical financial constraints that allow Vivianne Miedema to move for free to one rival, while allowing a potential era-defining defender to saunter to another? In a way, Arsenal’s approach when James started running at them was identical to their approach when Chelsea started raising the stakes for Girma: flap, panic, react and react and react and finally throw in the towel. Look, we tried to get the ball, what else can you do?

Where – for want of a better word – is the ambition? There is so much passion and colour and energy to tap into: a talented coach with time on her side and a wise head on her shoulders, fans who follow them everywhere, who would do anything for this club to be successful. But they’re going to need a bit of help from upstairs. Otherwise they’re going to keep finding out what the blue end of derby day feels like.