UCLA built a 20-point lead with 7:50 to go in the first period and then outscored the Dukes the rest of the way to the half 25-11.
The Bruins' lead at intermission was 63-29, allowing Powell and the rest of the UCLA starters to get plenty of rest during the second period.
UCLA improved to 3-0. It was the season opener for James Madison.
Powell made 9-of-12 shots from the field and finished with 24 points. Jordan Adams came off the bench to lead the Bruins in scoring with 28, a total produced in just 15 minutes. UCLA shot 60 percent from the field.
James Madison was paced by Rayshawn Goins with 24.