User blog comment:IamJakuhoRaikoben/Chapter 381: Where Demons Live, Review./@comment-24956965-20140418114153/@comment-7418318-20140418115144

In the entire series Lucy is one of the people who has to take the most damage and still barely ever gets beaten down so bad that she can't get up anymore, so I wouldn't compare her with someone who was (possibly) just one-hit-KOed.

While she collapses after the fight is over several times, that's usually due to exhausting her magic, not due to being knocked out by the enemy.