The Gunners got off to a great start as a good attack from the left ended with Kim Little passing to Viktoria Belova to pass the ball to Beth Mead who moved on her left foot before firing into the roof of the goal in the eighth minute.
But Chelsea rallied back within five minutes when Johanna Retting-Canerede picked up the ball from the right and slotted it past Manuela Zinnsberger at the near post after cutting inside.
Caitlin Ford was denied at the far post by Little’s low ball across the face of goal, with Eve Perisset making a timely save to deny the Australian.
But Perisset’s foul on Ford earned the home side a free kick on the left of the penalty area midway through the first half, with Mead’s pass too deep to do any damage.
Arsenal continued to enjoy the lion’s share of the possession and Katie McCabe’s excellent ball across the field allowed Ford to play in Steve Catley but the visiting defense cut out her cross at the expense of a corner kick which also came to nothing.
The home side restored the lead from another corner kick in the 36th minute, after Ford saw a cross headed in behind her, with Amanda Ellstedt nodding home Catley’s right-hand pass.
The score was 3-1 after less than two minutes as Catley’s run found Alessia Russo, who raced into the penalty area on the left flank and opened up her body before firing a shot inside the far post.
Zinsberger had to be alert in the 45th minute to block a shot from Erin Cuthbert, with Sam Kerr lurking for the loose ball, to protect the goal cushion before the break.
Chelsea coach Emma Hayes made a triple change during the period, as Sjoyke Noskin, Maren Melde and Peresit were replaced by Fran Kirby, Kadisha Buchanan and Ashley Lawrence.
Lauren James sent a shot long range three minutes into the second half as the visitors looked to respond.
McCabe received her fourth yellow card of the season for disputing a decision made against her by referee Rebecca Welsh, with Ford being booked shortly after.
Jonas Edvall was forced to make his first substitution after around the hour mark, as Little, making her 299th appearance for the club, came off as a precaution to be replaced by Frida Mannum.
Catley was left scowling moments later after a vital sliding tackle denied Rytting Kaneryd another shot on target inside the box, but she was able to carry on.
Leah Walti suffered a painful metatarsal injury when James stood on her left foot and was booked, with Lawrence denied a shot on target by a recovering home defense after playing down the right flank in a Chelsea counter-attack.
Arsenal were awarded a penalty in the 72nd minute when Rousseau went down under the challenge of Anne-Katrin Berger as she looked to catch Belova’s pass inside the box, with Jess Carter pushing the ball wide.
With Little off the field, Rousseau slotted the penalty into the bottom left corner of the goal with composure and confidence to make it 4-1 and end a run of four consecutive penalties missed by Arsenal.
This turned out to be Rousseau’s final contribution to the cause which made way for Stina Blackstenius in the triple switch, which also saw Mead and Catley replaced by Chloe Lacasse and Noelle Maritz.
Maritz and Mannum received other yellow cards in the final minutes, and Blackstenius wasted a good opportunity to add the fifth goal in the 86th minute when she shot it outside the right post.
Belova picked up Arsenal’s fifth yellow card of the game when she brought down Cuthbert shortly after, but then sent Lacasse in from the right before he cut back and passed to Ford, whose shot was deflected backwards.
Chelsea had another chance when Blackstenius headed a ball wide of the goal from a Maccabi free kick in stoppage time, before Zinnsberger easily blocked headers from Mia Fishel and Kerr at the other end before the final whistle.
Arsenal: Zinnsberger, Maccabi, Wobin Mooy, Elstedt, Catley (Maritz 75), Belova (Koni Kroos 90), Altai, Mead (Lacasse 76), Little (Manum 61), Ford, Rousseau (Plaxenius 75). Unused subs: Petit, Miedema, D’Angelo, Codina.
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