The WSL is often described as a three-tier league made up of the battle to avoid relegation, the fight for the title and the struggle to be best of the rest. That is not the reality though, because there is no competition at the top and Chelsea are operating in a league of their own above the rest.

The 1-0 win for Sonia Bompastor’s side over Arsenal was testament to that, their domination – even in a year of change – means they remain unbeaten and sit pretty at the top.

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

To rub salt in the wounds, Naomi Girma, a player the US manager Emma Hayes described as the best defender she’s ever seen and someone Arsenal were priced out of the running for, was unveiled to the fans on the Stamford Bridge pitch prior to kick-off, her recruitment to an already stacked side symbolic of the gap between the Blues and the rest.

It wasn’t totally straightforward for the hosts as the rain came down, they needed their bench to navigate their way past the resurgent Gunners, Lauren James providing the impetus, forcing Kim Little into conceding a penalty that fellow substitute Guro Reiten would convert to deliver victory, Katie McCabe sent off for dissent in the process.

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

From an Arsenal point of view, this fixture was pitched as a chance to exorcise the ghost of their poor start to the season, the nadir of which was a 2-1 defeat to Chelsea in the reverse fixture, a loss that would trigger Jonas Eidevall’s resignation three days later and begin the ‘Reneeissance’. The visitors were unbeaten under interim turned permanent manager Renée Slegers, having won 12 of their 13 games and scored 40 goals in all competitions between Eidevall’s exit and the loss to Chelsea.

Win, and the gap would close to four points, lose and it would grow to 10. “We need to beat Chelsea really, it’s as simple as that,” Arsenal’s captain Little had said succinctly, prior to the meeting in front of a crowd of 34,302 fans at Stamford Bridge.

Unfortunately, the task was far less simple, the Gunners had failed to win any of their past five WSL games away at Chelsea, a run stretching back to their thumping 5-0 defeat of the Blues under Joe Montemurro in October 2018, and that run would be extended.

Slegers had warned that the game would be won by the team that could “manage the tough spells in the best way” and it seemed as if Arsenal wanted to test that theory from the off, the back line rattled as they attempted to hold off charge after charge.

Within a minute the Gunners were under intense pressure, the Colombian forward Mayra Ramírez forcing Leah Williamson into a short unguided pass that she would pounce on before the ball was worked to Catarina Macário and Daphne van Domselaar got down well to deny the US international. It was a warning, but the Chelsea press was physical, fast and relentless, and Arsenal just did not look like they could cope.

“From our end, we needed to get through that first 10 minutes,” said Slegers. “We knew Chelsea would come out fast, get in behind us and go forward. That’s what they did. They are very powerful so I’m happy the girls got through that phase of the game.”

The visitors emerged into daylight after 20 minutes, a stray Cuthbert ball back towards goal played straight to Alessia Russo who glided round England teammate Millie Bright before placing her effort wide of the far post. It was the boost Slegers’ side needed, and they arguably had the best chances of the first half.

Related: Chelsea’s Guro Reiten: ‘We’re not happy with where we are right now’

The second half was far more even, the substitute Frida Maanum’s effort coming back off the crossbar the clearest chance.

It would be the introduction of James, for the first time since October, that would swing the balance in Chelsea’s favour, the seemingly unplayable 23-year-old swept into the box from the right and was downed by Little giving the referee Emily Heaslip no option but to point to the spot. In stills circulating online it looked like Little may have grazed the ball, but without VAR it would have been hard to see.

“Lauren is a player who is really creative with the ball, I don’t need to teach her anything, she knows,” said Bompastor. “When you have these tight games she can make the difference, and small details are really important.”

McCabe received two bookings in quick succession for foul and abusive language before Reiten converted the penalty.

In the end, that would be the fine margin that separated them, but the reality is the gap is far, far greater. Arsenal were far from humiliated, but Chelsea are just a different beast, their strength in depth the envy of all others.

They romp on unbeaten, their sights set one game ahead as talk of a quadruple grows.