The burglar was able to escape, the Belleville News-Democrat reported.
The woman told Fairview Heights police she was returning home with a friend Monday morning when she spotted a strange car parked outside the house and signs of a break-in. Her friend called 911 on her cellphone.
When a man emerged, he tried to grab the phone. The other woman struck him with her cane until he retreated and took off, damaging his car in the process.
Police did not give exact ages but said both women are over 70.
NASA celebrates Earth Day with #GlobalSelfie
Lytro unveils camera that can focus a photo after shooting it