An elderly woman, aged 84, has been left with serious injuries following an unprovoked assault in the southern suburbs of Adelaide.

The incident occurred yesterday afternoon as she stood by the traffic lights in South Plympton. CCTV footage captured the distressing moment a young man approached and struck her on the side of the head, causing her to collapse to the pavement.

The security video reveals the woman patiently waiting to cross the bustling Marion Road when, around 3:50 p.m., a man emerges from a side street and heads her way.

In a shocking and seemingly unprovoked act, he delivers a punch that sends her to the ground before he casually continues along the footpath, behaving as if nothing had transpired.

Fortunately, several Good Samaritans who witnessed the attack immediately rushed to assist the injured woman.

Remarkably, she got up and started walking away, still under the watchful eye of concerned witnesses. 

She was eventually taken to hospital with serious injuries. 

A 31-year-old Edwardstown man was charged with aggravated assault causing harm and refused bail to face court.

The attack he’s accused of perpetrating sparked outrage among locals.

Police asked anyone who might have witnessed the incident or have video of it, including dashcam footage, to come forward.