Villanueva was 3-of-6 from three-point territory and also had seven rebounds and two steals in under 22 minutes.
The Pistons led by 19 points after two quarters but their lead quickly diminished in the third as a Jordan Crawford jumper cut Detroit's lead to 64-58 with 3:51 remaining in the quarter.
After the Pistons entered the fourth with a 10-point lead, Crawford hit a three with 5:15 remaining in the quarter to cut Detroit's lead to 88-81 but that was as close as Washington could get in the final two quarters.
Crawford finished the game with 21 points on 4-of-13 shooting from the field. The loss was Washington's seventh in a row as they fell to 3-22 on the season.
This is only the second time this season that the Pistons have won back-to-back games. They also accomplished the feat on Nov. 26 and 28 when they defeated Portland and Phoenix at home. The win improved Detroit to 9-21 this season.