Villanueva picked up the slack, however, and Andrew Bogut added 21 points in helping the Bucks end a three-game losing streak.
Seattle, which has lost six of seven, was led by 22 points from Kevin Durant.
The SuperSonics trailed by 15 entering the fourth quarter, but got within five with 2:49 remaining. The Bucks then ran off seven straight points to clinch the game.
Villanueva scored 10 points in a 14-0, first-period run.
2014: NFL Cheerleaders [PHOTOS]
Michael Sam cut from the Dallas Cowboys