Yvette Talbot, 54, was walking from her work in Halifax town centre when she was grabbed from behind by a man who snatched her handbag at around 10.30pm last night.
She suffered facial injuries as she was thrown into the road.
The incident took place on Prescott Street, close to Halifax Swimming Pool on Skircoat Road.
A taxi driver stopped to help her, as did a man of Eastern European nationality, who attempted to stop the suspect.
"It all happened so fast," she said, "I was talking on my phone on the way to buy some food. He just came up behind me and grabbed me.
"He grabbed hold of my bag and threw me into the road onto the ground.
"A police car was coming down the road on its way to another job and stopped. The taxi driver flagged them down."
Moments later a 17-year-old was found hiding in a garden and was arrested. He remains in police custody.
The £350 designer handbag was returned to Yvette with all items intact, aside from a broke iPhone.
"My face is sore and swollen and I just feel really achy. I'm alright, a bit shaken up.
"I don't know why I didn't just let go of the bag. There was no cash in it - maybe £3 - but you don't think that way, do you?
"I'd like to thank the men who helped me and I'd like to ask them to go to the police and tell them anything they saw."