After an end-to-end first half, Arsenal made a change at the break, sending on Blackstenius in place of Maanum - and the substitute made an instant impact. Receiving a back-heel from Russo inside the box, the No25 slotted the ball past Megan Walsh in the West Ham goal to give the Gunners an early second-half advantage.
Walsh came to the east Londoners' rescue just moments later, swiping the ball clear of an unmarked Foord in the area, who had earlier had a goal disallowed for offside, before Mead swept an effort from close range wide of the post.
Although Foord was denied by the flag earlier in the second half, she netted Arsenal’s third just after the hour mark, meeting Caldentey’s delivery with a header into the roof of the net.
The Gunners threatened to net a fourth when a Katie McCabe delivery flashed across the face of goal before Blackstenius almost got on the end of Foord’s low cross.
But indeed, their fourth did arrive through last season’s top scorer Russo, who fired a long-range strike past Walsh, before the No23 was given the chance to net her second of the evening after Inès Belloumou conceded a penalty in stoppage time. Walsh went the right way, but Russo still tucked the ball home.
The Hammers shot-stopper had to be alert right until the last second, as she kept out an effort from Blackstenius in the 96th minute.
West Ham United: Walsh, Denton, Zadorsky, Nyström (Paví 75), Tysiak, Hanshaw (Belloumou 65), Gorry ©, Siren (Wandeler 86), Asseyi, Martinez (Piubel 65), Ueki
Subs not used: O’Hanlon (GK), Endo, Csiki, Brasero, Morgan
Goal: Van Domselaar OG 5
Booked: Gorry
Arsenal: Van Domselaar, Fox, Catley (Wubben-Moy 89), Caldentey (Pelova 79), Mead (Smith 63), Little ©, McCabe (Hinds 79), Maanum (Blackstenius 46), Foord, Russo, Reid
Subs not used: Zinsberger (GK), Borbe (GK), Codina, Cooney-Cross
Goals: Maanum 21, Blackstenius 52, Foord 62, Russo 90, 90+3
Referee: Megan Wilson
Attendance: 3,483