From the January 1980 issue of the Avengers :
Scarlet Witch, the Wasp, and Ms. Marvel all get KOed by the Grey Gargoyle! The Wasp scene is pretty much worthless, due to her tiny size, but the scenes with Wanda and carol are very good. The two full-size heroines are depicted unconscious and there is a nice wake-up sc...
From the April 1979 issue :
Hawkgirl KOs a Valkyrie; Hawkgirl and Wonder Woman are blasted out cold; Zatanna's mother Sindella passes out (dies?) and is cradle carried.
Source: My Collection
A woman being possessed by a crazy guy with a medallion in this issue. Sara and her partner track him down and stop him. The woman passes out off panel unfortunately.
From Justice League of America, Volume 1, Issue #141 (DC, April 1977) :
An energy discharge from a Manhunter takes Black Canary down. There is a shot of her out cold on the ground, recovering, but still looking groggy (needing to sit). When we next see her, she has been subdued again, and is unconscious. Wonder Woma...
Not an Avenger KO scene this time, but a guest star, Marvel Girl (Jean Grey) from the X-Men! Marvel Girl is found unconscious, and gets cradle-carried.
Avengers, Volume 1, Issue #110 (April 1973)
Source: My Collection
Here is some excellent George Perez art from Avengers, Volume 1, Issues #147-149 (Marvel, May-July 1976). Knockouts featuring the Scarlet Witch, Hellcat, Moondragon, and also Lady Lark of the Squadron Supreme!
Source: My Collection
Cassie Sandsmark, the new Wonder Girl, is attacked by her own armor..Red Robin and Superboy help her get out of the armor, leaving her in her skivies...an old boyfriend shows up and runs off with her costume...leaving her extremely upset..kinda kinky for a mainstream book!
Source: blog
In this self-contained story, Sonja has been defeated by a warrier woman named Raven (not shown, unfortunately), and is tied to a tree. This issue features Red tied up for about half the time..
Source: blog
From the December 1971 issue of Justice League of America -- Black Canary is punched by a mind-controlled Green Arrow, and put into bondage. It isn't technically a knockout scene -- but I know that you guys like to see the Canary tied up!
Source: My Collection
From the February 1973 issue of Justice League of America -- the Black Canary is KOed twice! First, she is rendered unconscious by the "Gamma Gong" (the dangerous device is being telekinetically manipulated by the villainous Hector Hammond). Later on, she gets a squeeze from the Shaggy Man, and passes out in the monstr...
Spider Woman - in an early appearance - is nearly drowned, blasted and finally KO'd by Alicia masters, who herself has been turned into a spider-monster.