The woman was stood outside the supermarket when she was approached by a man.
He led her to a nearby bench and raped her.
The man is described as approximately 5ft 6ins tall, Asian, of medium build with a short beard and black hair.
He was wearing a black overcoat with dark jeans and a brown belt.
The woman is receiving support from specially trained officers and enquiries into the incident are ongoing.
Detective Sergeant David Jones, of GMP’s Trafford borough, said:
“We have launched an investigation and have a team of dedicated officers working tirelessly to find the man responsible.
“This was a horrific attack on an innocent woman and we need the public’s help. If you saw anything or have any information that could assist our investigation, please get in touch as a matter of urgency.
“We have quite a detailed description of the man, so we are hoping that someone will have seen him in the area. Even if you aren’t sure if your information could help, please get in touch as even the smallest piece of information could prove vital.”
Anyone with information should contact police on 101 quoting incident number 646 of 04/02/2018, or the independent charity Crimestoppers, anonymously, on 0800 555 111.