A woman CAN beat a man if she has a substantial enough skill/experience advantage. There was a MMA fight awhile back where a very prominent woman MMA fighter fought a male MMA fighter who was…not bad, but more of a regional big deal than a worldwide big-deal. The male was small by male standards, but still larger than the woman. He had a size and reach advantage, but not a huge one. She was one of the best female MMA fighters.
He kicked her a—.
But could she have beaten a ‘regular joe’? Or a BAD MMA fighter? YES! The disadvantages a woman has in these situations are real, but they’re not infinite. You could have your female character surprise the man and injure him right at the start enough that it evens the odds. Or maybe the gap in skill is THAT large. Maybe the man has a pre-existing injury?
Or maybe he underestimates her. This is a very real thing, men underestimating women is definitely a thing that happens. This would allow her to strike a vital area (avoid kick to the groin…too cliche) to even the odds. Perhaps she’s well armed, and he’s not? There are ways to make this work.
Now all of that is if you’re trying to make it a RELATIVELY fair fight. If it’s not…I mean, anyone can slice a carotid artery if they know where to cut. Put a blade through a lung and collapse it…that person’s not going to fight well afterwards. Cut an achilles tendon?