Arsenal failed to clear their lines after Chelsea applied some early pressure, and a deep cross from Guro Reiten was nodded over the line by Sam Kerr – her ninth goal in five finals for the Blues.
That same combination nearly saw Chelsea add a second soon after, though this time Kerr’s header fell straight into the gloves of a grateful Manuela Zinsberger.
At the other end, Millie Bright deflected teasing Arsenal crosses behind at the near post three times in as many minutes as the Gunners looked to find a leveller.
Chelsea were quaking and nearly conceded a third when Steph Catley’s high improvised cross was nodded on by Blackstenius, but she was denied this time by Berger.
Just after the half-hour mark, Arsenal had the ball in the net again after Catley again picked out Blackstenius with a superb whipped ball, directing it into the far-hand corner, only to be denied by a late offside flag.
But that didn’t stop Arsenal extending their lead, with Rafaelle rising to head a Catley corner in off of Niamh Charles in stoppage time.
Just after the break, Erin Cuthbert snuck into the box and nearly guided in a Reiten cross with an instinctive volley, but the ball bounced narrowly wide instead.
Kerr was so nearly set racing away against Zinsberger by Lauren James, but she was denied by a last-ditch challenge by Rafaelle.
Substitute Victoria Pelova nearly notched Arsenal’s fourth with her first touch, but Berger got down low to keep out her half-volley.
The Gunners were incensed that they weren’t awarded a penalty when Buchanan clearly fouled Caitlin Foord, instead receiving a corner.
For the first time in the second half, Zinsberger came to Arsenal’s rescue when she flew across her line to palm away a wicked half-volley from Melanie Leupolz.
The Germany saw a cross bounce back off the upright late on, with Zinsberger scrambling to ensure it didn’t drop back into the net.