@JJ
JJ - between you and me - if the perpetrator is seriously injured - it just means they got lucky and survived.
Listen to JJ - voice of experience.
If you can't run away - you need to be violent, without hesitation, conscience, remorse, pity, or compassion. If you cannot be violent - expect imminent or near future retaliation. If you decide to defend yourself - you must be fast - speed is essential - and deadly - use full force and deadly force.
If you don't have this mentality - then by all means, try to run away (usually you'll be cornered though) - or try the PASSIVE AGGRESSIVE SOLUTION at the bottom of this comment. Weigh the costs of your actions (also called paranoia), then commit to your response - aka plan for the worst. If you become the victim - at worst you'll be a cadaver on a morgue slab. If you survive the attack, expect a protracted hospital stay, potential permanent disability, and serious mental issues - depression, fear, nightmares, paranoia, dementia, etc.
AGGRESSIVE SOLUTION
As for spray and run - it's wishful thinking but risky. If the situation calls for a spray in the face - it is only a temporary stun. IF you have the ability and the courage, spray to temporarily stun, then put your opponent down hard and semi-permanently to permanently - make sure they won't be getting up for the next 10-20 minutes so you can leisurely stroll away. And remember this - spraying the face means you have to practice - that means make sure you aim and spray in the right direction. Under duress - you may inadvertently spray yourself.
Why run when you can stroll.
That means do some serious and critical body damage - so even if they can get up again - their ability to harm you will have to wait until they leave the hospital - broken arm, broken leg, crushed hand, broken ankle, smashed face - whatever's convenient and strikes your fancy - but never hesitate.
If you have the time and you want to be legal about the whole thing (which is really troublesome), search the body for ID and drop it off at the local police station along with your report of attempted robbery, mugging, etc. They'll find the culprit at one of the local hospitals. But again, this will be really troublesome for you. Doing the right thing is always troublesome.
PASSIVE AGGRESSIVE SOLUTION
Barf all over yourself first and if you still have some spare gag response, aim the second stream at the aggressor - instead of moving away, move towards the aggressor so you can get a really good shot at their face and body.
They usually won't want to touch you because of the stench (bile, vomit, etc) and will actually back away. Vomit is particularly more effective in the face and eyes than any pepper spray or alcohol derivative.
This advice is usually given to potential rape victims. Vomit makes one particularly unattractive in both appearance and smell - should render most perps somewhat impotent - although rape is said to be a crime of violence. The shock of such an action should be sufficient to stun even the most hardened of criminals.
The additional benefit is vomiting doesn't require too much practice - most people can induce an excellent hurl with the traditional finger down the throat. If you have a handbag or backpack - hurl on that too.
That said - I'm a major fan of China's death penalty - swift justice - even given the potential for judicial error or other force majeur issues such as corruption.
INNOCUOUS LEGAL WEAPONS - MEDIUM TO LONG RANGE
A walking stick - if you know how to use it. There are martial arts training for walking stick combat. Just make sure the stick is made of a solid hardwood - not the crappy bamboo or hollow aluminum junk that's sold by street vendors. Ebony, walnut, maple (?) - dense hardwoods. To make sure it works - whack a local tree (big tree) with all your strength - if the stick buckles or breaks - better to know before you try to use it in combat.
INNOCUOUS LEGAL WEAPONS - SHORT RANGE
Your keys - these things are nastier than brass knuckles - hold the keys between your fingers - so they look like claws. Do NOT punch to the face - punch the eyes or the throat and do it fast, with strength, commitment, and without hesitation...and don't miss. There's also rape avoidance training on how to use simple house/car keys as personal defense weapons. You can practise key kungfu on your pillow or stuffed animal (or your shadow).
ENJOY...and be safe (which usually means a certain element of paranoia aka situational awareness).