After the woman fell back on the sofa, the intruder put duct-tape on her mouth and around her wrists.
He threatened her with a syringe filled with a clear liquid, warning that he would stick her if she didn't give him what he wanted.
But during the tussle, the robber had pulled off the grandmother's medic-alert necklace, immediately sending a 911 message at 10:05 a.m. to police. A niece who was out of town and her designated next-of-kin, was also alerted.
As the intruder ran into a waiting car with another male at the wheel, neighbors who heard the commotion got a good look at him.
Calling the crime "heinous," Lt. Michael Gross of Northeast Detectives said two men - 31 and 27, with records for narcotics arrests - were in custody and would be charged with aggravated assault, robbery and burglary.
One of the suspects, he said, is her grandson.
The woman, who lived in the 2800 block of Unruh Street, was taken to Aria Health-Frankford Campus. Police said she was in stable condition and treated for abrasions, bruises and swelling.
A niece had gone to the hospital to be with her aunt, Gross said, and two other nieces from out of town were on their way.
Gross said the suspects were picked up at the home of the grandson in the 3200 block of Tyson Avenue. "They tried to implicate each other," Gross said.
Police believe the grandson was driving the getaway car and his friend was his grandmother's attacker.Gross said the woman told police that her grandson owed her thousands of dollars. "There was friction," he said.
At the grandson's house, police found the woman's purse and jewelry in trash can.
Police said it was all costume jewelry.
Contact staff writer Jennifer Lin at 215-854-5659 or firstname.lastname@example.org, or on Twitter @j_linq.