Two female assassins are knocked out and bound and gagged. Art by Amanda Conner.

The protagonist drugs a rich delinquent girl from the tennis club, in order to avenge his friend who got brutally beaten by her and her gang of girls with tennis rackets. Again the scene is fantastic. A funny thing to note, the chloroform was provided by the nurse from ch.2, who became his "ally". Source: g.e-hentai.o...

A school nurse who harasses little boys coming for treatment gets the table turned on her by the protagonist (yes, he is the good guy here), who manage to swipe the soaked cloth and drug her. It turned out the boys she tormented asked him to punish her. The scene is excellent in all terms, but I had to cut the 4th pag...

A school girl gets chloroformed by the seemingly gentle boy. Nice pass-out shot. Source: g.e-hentai.org

Lois Lane is knocked out by some thugs. They later bind and gag her.

Light Lass is ambushed and KO'd. Added as requested. Source: Comic

It's Hope Summers vs Scarlet Witch and when the fight appears to be ended in a draw, Hope sucker punches Scarlet Witch to win the fight.

Cinnamon and her friend are hit in the head and carried OTS into a mine

Marvel Girl and Grifter are attacked by Pike and Mr. Sinister.

"What If Storm had the power of the Phoenix?" Jean Grey is knocked out before the X-Men get to the shuttle, so Storm pilots it instead.

Madame Masque is bound and gagged by Kate Bishop, who steals her costume in order to impersonate her.

Couldn't find this one on here, but I may be wrong. Wonder Woman is zapped in her inner ear with a mind controlling devise that makes her believe she's in combat with a deadly opponent...some nice unconsious pics.. Source: blog

Amanda Waller falls unconscious from some poison rain by the Joker.

This book on how to draw contains some sample sleepy art.

A lady is chloroformed while in the restroom of an airport. This manga volume also has a nice splash page featuring an unconscious girl.

I've been looking for this scene for years and finally found it! In the first volume of this extremely violent manga, a sexy lady in glasses is chloroformed during a fight sequence. She is next seen naked in a bed.

I thought this was a nice cover, which depicts Blackfire choking her sister Starfire.

Cover of trade paperback, releases in 2013.

Victoria Hand is carried unconscious by Captain Marvel. Later on she is awakened by Doctor Strange.

Poison Ivy and Batman are knocked out. Ivy through electricity, Batman through gas. Someone hired by the Penguin carries Ivy over the shoulder.