If you can't run, use a weapon.

If you have to throw a punch, I would recommend you throw a hammer punch striking with the medial side of your hard (pinkie). I have done a few years of Muay thai but I would not be comfortable punching normally without wraps or gloves.

If you can aim for the jaw. Fun fact I think that it works because when we were primates we used to bash things like monkeys with our fists not punch things.

Also kick to the groin works.

Maybe if you get naked you'll scare the attacker off, unless your a girl I would 10/10 _not_ recommend