Menifield's effort helped the Huskies get off to a 3-0 start for the first time since the 2015-16 season.
Washington used a pair of big runs to build an advantage the Wildcats couldn't overcome.
The Huskies pulled away with 10 minutes left in the contest, going on a 16-2 run over six minutes.
It was a battle until the end, with PJ Fuller hitting a big three to put the Dawgs within three points with eight minutes remaining in the contest. In the end, the Cougars were able to pull away and get the win.
For the second consecutive game, the Huskies started hot against a top-20 opponent before faltering down the stretch. This time, the Dawgs dropped a road tilt against No. 17 USC, 79-69.