At about 2.40pm on Friday, June 30, the victim was walking on Worsley Mesnes Drive when she was approached by a woman she didn’t know.
The woman claimed the victim owed her £40 even though they had never met and the victim refused to pay.
The robber then attempted to grab the victim’s handbag before hitting her in the face several times.
She then threatened she was going to stab her although no knife was ever seen.
Another woman tried to intervene but the offender hit the victim again in her face and managed to grab her handbag before fleeing.
The bag contained £120 in cash as well as cards, keys and a mobile phone.
She is described as white, in her mid 20s, of slim build, about 5ft 10ins, had shoulder length curly hair which was a ginger/brown colour.
She spoke with a local accent and was wearing a black coat and blue jeans.
Police Constable Dave Bellis, from GMP’s Wigan borough, said: “This was a vicious attack in broad daylight on an innocent woman who was making her way back from the shops.
“She was understandably left extremely shaken by this.
“The person who stopped has been spoken to by police and has helped us with our enquiries.
“I would now ask anyone who recognises the description of the offender, or saw anything which could be to do with this attack, to please call us.”
Information can be passed on by calling 101 and quoting incident number 1229 of 30 June 2017.
Alternatively, details can be given anonymously to Crimestoppers on 0800 555 111.