The woman said she was at her home in the 1500 block of Inlet Court, about 10 p.m. when she discovered a man in the basement. The then suspect fled, police said.
The suspect was described as black, about 6 feet tall, thin build, wearing a white short-sleeve T-shirt and dark-colored pants.
The woman was unharmed. Police did not say whether any items were stolen from the home.
On June 17, police caught a man suspected of breaking into an apartment in the 11600 block of Stoneview Square.
A resident called police about 11 p.m. after an unknown man walked into her home through an unlocked door, police said.
Officers then located the man and arrested him. Philip A. Anderson, 30, of Reston, was charged with trespassing and entering property to damage.
In other crime news from the Reston District Station:
9900 block of Deerfield Pond, property from residence.
2300 block of Hunters Woods Plaza, phone from business.
11100 block of South Lakes Drive, merchandise from business.
12100 block of Stirrup Road, bicycle from residence.
2200 block of Springwood Drive, property from business.
13100 block of Parcher Avenue, merchandise from business.