Aaron Gordon had 18 points and 11 rebounds for the Wildcats (15-0, 2-0 Pac-12), who extended their best start to a season since 1932, when they began 16-0.
Arizona was coming off the one of the best defensive performances in team history in a 60-25 win over Washington State Thursday.
The Wildcats trailed 35-33 at halftime Saturday but held the Huskies to 30.3 percent shooting the rest of way to secure the win.
C.J. Wilcox led Washington (9-6, 1-1) with 20 points. Perris Blackwell had 12 points and 12 rebounds.