It happened Sunday afternoon as the woman, who doesn't speak English and is known to the building's residents as Mrs. Ye, returned to her apartment building in the Dundas Street East and Sherbourne Street area.
A man followed her through the security door into the lobby and offered to help the woman carry groceries to her apartment.
Police say the man then pushed the woman into her apartment, where he demanded cash and tried to take her ring.
When neighbour Chin-Hua Chen saw the man, he knew something was wrong.
"When she opened the door, he pushed her in. I heard her screaming. I came down here, charging. Of course he tried to hit me, because he's trying to get away."
With Chen trying to help, the tug-of-war then spilled over into the stairwell when another person, a homeless man who was squatting in the stairwell, joined the fight.
"He said 'I'm good, this bad man,'" Chen said, quoting the man.
Hearing the commotion and next to enter the fray was 71-year-old Jane Harris. She came armed with her cane which is equipped with a jagged steel edge for winter walking.
CBC News reporter Shannon Martin asked Harris where she jabbed the man with her cane. Her response: "In the man's genitals. I did not assault him. If he got hurt, it was of his wrongdoing."
Eventually police arrived and the man, 52, was arrested.
He faces the following charges:- Robbery.
- Assault causing bodily harm.
- Mischief under $5,000.
Mrs. Ye was treated in hospital for an injured finger. Police praised the people in the building who came to help the 82-year-old grandmother.
"It probably could have been much worse, if not for the bravery, if not for the people in her building," said Toronto police Staff Sgt. Dan Crosby. "They really need to be applauded."
The building requires an electronic security card to enter the lobby. The front door operates with a 30-second delay to allow the building's residents, many of whom are seniors, enough time to enter and exit.
"The problem is anyone can follow them in, and that's why residents want tighter security," Martin reported.
"Now it's a nightmare," said Harris. "The street people are coming in."