AT A BLOW
at a blow: translation
or[at a stroke] or[at one stroke] {adv. phr.} Immediately; suddenly; with one quick or forceful action. * /The pirates captured the ship and captured a ton of gold at a blow./ * /A thousand men lost their jobs at a stroke when the factory closed./ * /All the prisoners escaped at one stroke./ Compare: AT ONCE, AT ONE TIME.