The champions of England and Europe will do battle on Saturday, with the result having major ramifications for the Women's Super League title race.
Chelsea's hopes of a seventh consecutive WSL crown are under threat, with Manchester City currently six points clear of Sonia Bompastor's side at the top.
Arsenal are a further four points back of the Blues, and with just nine matchdays remaining after this one, any slim hopes Renee Slegers' team have of claiming the title will surely be over with anything less than a victory.
There will be plenty of familiar faces in competition at Stamford Bridge, with Chelsea and Arsenal having combined to provide 11 players in England's triumphant Euro 2025 squad.
Ahead of this mammoth showdown in west London, we delve into the Opta data to pick out the key players and storylines to watch.
What's expected?
The Opta supercomputer is firmly behind Chelsea ahead of this game, with the Blues winning 62.8% of its 10,000 pre-match simulations.
Arsenal are assigned a 17.5% chance of victory, while 19.7% of scenarios saw the points shared.
And going into matchday 13, the Opta supercomputer gives Chelsea a 27% chance of retaining their title, with Man City topping the pile in 71.7% of season simulations.
Arsenal's title hopes are down at 1.1%, and they are the only other team with even a one-in-a-hundred probability.
The omens are good for Chelsea, who are unbeaten in their last six WSL home games against Arsenal, winning five of those (one draw), since a 5-0 defeat in October 2018 – a loss that ended a 17-month unbeaten streak in league play.
The reverse fixture at Emirates Stadium, on matchday eight, finished 1-1, but the teams have never drawn both of their meetings in the same WSL campaign.
Chelsea have also lost just one of 23 WSL games played on a Saturday since 2017 (19 wins, three draws), losing 1-0 at Reading in December 2021. The Blues have won each of their last eight home league matches on Saturdays.
Big-game Blues have little margin for error
Man City have mounted arguably the sternest challenge to Chelsea's supremacy since they last failed to win the WSL in 2018-19, winning 11 straight games since losing to the Blues on matchday one.
With their title rivals in irresistible form, Bompastor's team simply cannot afford to drop more points, particularly as they visit City next weekend.
But Chelsea's tremendous record on the big stage should quell fears among the home fans.
Since the start of 2024-25, in games between the teams that made up last season's top four, Chelsea are averaging 2.6 points per game (nine games, seven wins, two draws).
The other sides involved have all averaged 1.1 points per game or fewer, with Arsenal averaging 1.1, Man City 0.9 and Manchester United 0.8.
Chelsea are unbeaten in their last 11 league matches against those three teams, too, since suffering a 1-0 home defeat to Man City in February 2024.
And they enter this game in strong form, having defeated City 1-0 on Wednesday to reach a seventh straight League Cup final – in what will be the final edition of the competition to feature teams involved in the Champions League.
Chelsea thumped West Ham 5-0 last time out in the WSL, with their figure of 4.11 expected goals (xG) being their highest in a WSL game since Bompastor joined the club – it was also the most comprehensive home victory of her reign.
Bompastor's win rate of 85% in WSL London derbies (13 games, 11 wins, two draws) is also the best figure of any manager to take charge of at least five such games.
Chelsea may not be top of the pile at present, but their big-game nous means they are still the team to beat in the WSL.
Arsenal face tense Williamson wait
While Bompastor has never lost a London derby in the WSL, the manager with the second-highest win rate in matches between capital clubs is Slegers (73%, 11 games, eight wins, two draws, one defeat).
But the Arsenal boss faces an anxious wait over the fitness of her captain ahead of this game.
Having recovered from knee surgery, Leah Williamson made her first start since the Lionesses' Euro 2025 final triumph on January 10, coming through 90 minutes as Arsenal drew 0-0 with Man Utd.
The England skipper previously suffered an anterior cruciate ligament tear in April 2023, which caused her to miss most of the 2023-24 campaign.
Williamson played over 1,200 minutes in five straight WSL campaigns between 2016-17 and 2021-22, but she has only passed that figure once in the last four (1,585 in 2024-25).
But her involvement in this one is also uncertain, after a calf strain she sustained in training caused her to miss Wednesday's League Cup defeat to Man Utd.
The Gunners' chances could be hugely impacted by her availability, or lack thereof. Since the start of last season, Arsenal hold a 72% win rate in the WSL when Williamson is in their starting lineup (13/18), compared to a 50% ratio without her (8/16).
Arsenal have also kept a clean sheet in 50% of their matches with Williamson starting (nine) in that period, compared to just 38% without her (six).
Despite being able to call upon Alessia Russo, Beth Mead, Frida Maanum, Stina Blackstenius and others, Arsenal have failed to score in two of their last four WSL games, drawing 0-0 with both Tottenham and Man Utd; and their 11% conversion rate this season is their worst in any WSL campaign since 2015 (10.3%).
With Olivia Smith suspended following her red card in the League Cup semi-finals, Arsenal's attacking prospects have taken a further blow. With that in mind, a solid defensive performance is paramount – with or without Williamson.
PLAYERS TO WATCH
Chelsea – Alyssa Thompson
Thompson could become the first American player to score in three consecutive WSL appearances, having netted in Chelsea's wins over Brighton and West Ham.
In addition, her first league goal for the Blues came against Arsenal last November and only three players have netted both home and away to the Gunners for Chelsea in the same campaign (Yuki Nagasato and Ji So-Yun in 2014 and Bethany England in 2019-20).
Arsenal – Alessia Russo
Since the start of the 2023-24 campaign, when Russo joined Arsenal, only Khadija Shaw (45) has scored more WSL goals than the England forward (29).
Russo has averaged a goal every 154 minutes in the competition in that time, the third-best figure among players to score at least 20 goals.
Shaw leads the way, scoring a goal every 74 minutes, with Chelsea's Aggie Beever-Jones (104) has the second-best rate.