Have you ever seen a woman knockout another?

[FeistyBeth]

Yes. There are multiple ways to do it. However I'm assuming the question was in regards to a strike?

First of all, if one fighter is worn down from various holds - particularly those that restrict breathing - or is already a bit loopy from head shots, she is more susceptible to being knocked out.

However, one can also be knocked out from a single strike, and depending where it lands it doesn't necessarily have to be a big power shot.